diff --git a/docs/v4/accounting/index.html b/docs/v4/accounting/index.html
index 17a6dad2..08161dec 100644
--- a/docs/v4/accounting/index.html
+++ b/docs/v4/accounting/index.html
@@ -6340,7 +6340,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Accounting"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Accounting"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="Accounting"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="Accounting"><a href="#api-Accounting">Methods</a></li>
               <li data-group="Accounting" data-name="createAccount" class="">
                 <a href="#api-Accounting-createAccount">createAccount</a>
diff --git a/docs/v4/appstore/index.html b/docs/v4/appstore/index.html
index 97c52f88..49fe9676 100644
--- a/docs/v4/appstore/index.html
+++ b/docs/v4/appstore/index.html
@@ -1237,7 +1237,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="AppStore"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="AppStore"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="AppStore"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="AppStore"><a href="#api-AppStore">Methods</a></li>
               <li data-group="AppStore" data-name="getSubscription" class="">
                 <a href="#api-AppStore-getSubscription">getSubscription</a>
diff --git a/docs/v4/assets/index.html b/docs/v4/assets/index.html
index dfb77fba..63a84b70 100644
--- a/docs/v4/assets/index.html
+++ b/docs/v4/assets/index.html
@@ -1415,7 +1415,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Asset"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Asset"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="Asset"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="Asset"><a href="#api-Asset">Methods</a></li>
               <li data-group="Asset" data-name="createAsset" class="">
                 <a href="#api-Asset-createAsset">createAsset</a>
diff --git a/docs/v4/files/index.html b/docs/v4/files/index.html
index 9ff3f41e..b25b0bba 100644
--- a/docs/v4/files/index.html
+++ b/docs/v4/files/index.html
@@ -1144,7 +1144,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Files"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Files"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="Files"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="Files"><a href="#api-Files">Methods</a></li>
               <li data-group="Files" data-name="createFileAssociation" class="">
                 <a href="#api-Files-createFileAssociation">createFileAssociation</a>
diff --git a/docs/v4/finance/index.html b/docs/v4/finance/index.html
index e9864ca1..f07c0b97 100644
--- a/docs/v4/finance/index.html
+++ b/docs/v4/finance/index.html
@@ -2712,7 +2712,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Finance"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Finance"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="Finance"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="Finance"><a href="#api-Finance">Methods</a></li>
               <li data-group="Finance" data-name="getAccountingActivityAccountUsage" class="">
                 <a href="#api-Finance-getAccountingActivityAccountUsage">getAccountingActivityAccountUsage</a>
diff --git a/docs/v4/payroll-au/index.html b/docs/v4/payroll-au/index.html
index 48fc2ef5..503557b0 100644
--- a/docs/v4/payroll-au/index.html
+++ b/docs/v4/payroll-au/index.html
@@ -3411,7 +3411,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="PayrollAu"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="PayrollAu"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="PayrollAu"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="PayrollAu"><a href="#api-PayrollAu">Methods</a></li>
               <li data-group="PayrollAu" data-name="approveLeaveApplication" class="">
                 <a href="#api-PayrollAu-approveLeaveApplication">approveLeaveApplication</a>
diff --git a/docs/v4/payroll-nz/index.html b/docs/v4/payroll-nz/index.html
index b323c372..068fa4dd 100644
--- a/docs/v4/payroll-nz/index.html
+++ b/docs/v4/payroll-nz/index.html
@@ -4083,7 +4083,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="PayrollNz"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="PayrollNz"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="PayrollNz"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="PayrollNz"><a href="#api-PayrollNz">Methods</a></li>
               <li data-group="PayrollNz" data-name="approveTimesheet" class="">
                 <a href="#api-PayrollNz-approveTimesheet">approveTimesheet</a>
diff --git a/docs/v4/payroll-uk/index.html b/docs/v4/payroll-uk/index.html
index b54c1b4c..8e4eaf59 100644
--- a/docs/v4/payroll-uk/index.html
+++ b/docs/v4/payroll-uk/index.html
@@ -3696,7 +3696,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="PayrollUk"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="PayrollUk"><strong>VSN: </strong>12.3.0</li>
+              <li class="nav-header" data-group="PayrollUk"><strong>VSN: </strong>12.3.1</li>
               <li class="nav-header" data-group="PayrollUk"><a href="#api-PayrollUk">Methods</a></li>
               <li data-group="PayrollUk" data-name="approveTimesheet" class="">
                 <a href="#api-PayrollUk-approveTimesheet">approveTimesheet</a>
diff --git a/pom.xml b/pom.xml
index 72d95382..04104fe9 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
     <artifactId>xero-java</artifactId>
     <packaging>jar</packaging>
     <name>xero-java</name>
-    <version>12.3.0</version>
+    <version>12.3.1</version>
     <url>https://github.com/XeroAPI/Xero-Java</url>
     <description>This is the official Java SDK for Xero API</description>
     <licenses>
diff --git a/src/main/java/com/xero/api/client/AccountingApi.java b/src/main/java/com/xero/api/client/AccountingApi.java
index 554b725a..d1c36a2f 100644
--- a/src/main/java/com/xero/api/client/AccountingApi.java
+++ b/src/main/java/com/xero/api/client/AccountingApi.java
@@ -102,7 +102,7 @@ public class AccountingApi {
   private ApiClient apiClient;
   private static AccountingApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(AccountingApi.class);
 
   /** AccountingApi */
@@ -255,7 +255,6 @@ public HttpResponse createAccountForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Accounts");
     String url = uriBuilder.build().toString();
@@ -386,7 +385,6 @@ public HttpResponse createAccountAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -529,7 +527,6 @@ public HttpResponse createAccountAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -674,7 +671,6 @@ public HttpResponse createBankTransactionAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -819,7 +815,6 @@ public HttpResponse createBankTransactionAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -957,7 +952,6 @@ public HttpResponse createBankTransactionHistoryRecordForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1095,7 +1089,6 @@ public HttpResponse createBankTransactionsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/BankTransactions");
     if (summarizeErrors != null) {
@@ -1245,7 +1238,6 @@ public HttpResponse createBankTransferForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/BankTransfers");
     String url = uriBuilder.build().toString();
@@ -1375,7 +1367,6 @@ public HttpResponse createBankTransferAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1517,7 +1508,6 @@ public HttpResponse createBankTransferAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1654,7 +1644,6 @@ public HttpResponse createBankTransferHistoryRecordForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1781,7 +1770,6 @@ public HttpResponse createBatchPaymentForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/BatchPayments");
     if (summarizeErrors != null) {
@@ -1931,7 +1919,6 @@ public HttpResponse createBatchPaymentHistoryRecordForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2066,7 +2053,6 @@ public HttpResponse createBrandingThemePaymentServicesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2201,7 +2187,6 @@ public HttpResponse createContactAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2342,7 +2327,6 @@ public HttpResponse createContactAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2461,7 +2445,6 @@ public HttpResponse createContactGroupForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/ContactGroups");
     String url = uriBuilder.build().toString();
@@ -2588,7 +2571,6 @@ public HttpResponse createContactGroupContactsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2719,7 +2701,6 @@ public HttpResponse createContactHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2846,7 +2827,6 @@ public HttpResponse createContactsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Contacts");
     if (summarizeErrors != null) {
@@ -3003,7 +2983,6 @@ public HttpResponse createCreditNoteAllocationForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3175,7 +3154,6 @@ public HttpResponse createCreditNoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3353,7 +3331,6 @@ public HttpResponse createCreditNoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3506,7 +3483,6 @@ public HttpResponse createCreditNoteHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3641,7 +3617,6 @@ public HttpResponse createCreditNotesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/CreditNotes");
     if (summarizeErrors != null) {
@@ -3788,7 +3763,6 @@ public HttpResponse createCurrencyForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Currencies");
     String url = uriBuilder.build().toString();
@@ -3912,7 +3886,6 @@ public HttpResponse createEmployeesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Employees");
     if (summarizeErrors != null) {
@@ -4054,7 +4027,6 @@ public HttpResponse createExpenseClaimHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -4171,7 +4143,6 @@ public HttpResponse createExpenseClaimsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/ExpenseClaims");
     String url = uriBuilder.build().toString();
@@ -4317,7 +4288,6 @@ public HttpResponse createInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -4488,7 +4458,6 @@ public HttpResponse createInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -4641,7 +4610,6 @@ public HttpResponse createInvoiceHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -4774,7 +4742,6 @@ public HttpResponse createInvoicesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Invoices");
     if (summarizeErrors != null) {
@@ -4936,7 +4903,6 @@ public HttpResponse createItemHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -5068,7 +5034,6 @@ public HttpResponse createItemsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Items");
     if (summarizeErrors != null) {
@@ -5227,7 +5192,6 @@ public HttpResponse createLinkedTransactionForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/LinkedTransactions");
     String url = uriBuilder.build().toString();
@@ -5361,7 +5325,6 @@ public HttpResponse createManualJournalAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -5507,7 +5470,6 @@ public HttpResponse createManualJournalAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -5644,7 +5606,6 @@ public HttpResponse createManualJournalHistoryRecordForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -5773,7 +5734,6 @@ public HttpResponse createManualJournalsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/ManualJournals");
     if (summarizeErrors != null) {
@@ -5932,7 +5892,6 @@ public HttpResponse createOverpaymentAllocationsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -6085,7 +6044,6 @@ public HttpResponse createOverpaymentHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -6199,7 +6157,6 @@ public HttpResponse createPaymentForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Payments");
     String url = uriBuilder.build().toString();
@@ -6327,7 +6284,6 @@ public HttpResponse createPaymentHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -6450,7 +6406,6 @@ public HttpResponse createPaymentServiceForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PaymentServices");
     String url = uriBuilder.build().toString();
@@ -6572,7 +6527,6 @@ public HttpResponse createPaymentsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Payments");
     if (summarizeErrors != null) {
@@ -6729,7 +6683,6 @@ public HttpResponse createPrepaymentAllocationsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -6882,7 +6835,6 @@ public HttpResponse createPrepaymentHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7019,7 +6971,6 @@ public HttpResponse createPurchaseOrderAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7163,7 +7114,6 @@ public HttpResponse createPurchaseOrderAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7298,7 +7248,6 @@ public HttpResponse createPurchaseOrderHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7427,7 +7376,6 @@ public HttpResponse createPurchaseOrdersForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PurchaseOrders");
     if (summarizeErrors != null) {
@@ -7576,7 +7524,6 @@ public HttpResponse createQuoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7716,7 +7663,6 @@ public HttpResponse createQuoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7848,7 +7794,6 @@ public HttpResponse createQuoteHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7975,7 +7920,6 @@ public HttpResponse createQuotesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Quotes");
     if (summarizeErrors != null) {
@@ -8116,7 +8060,6 @@ public HttpResponse createReceiptForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Receipts");
     if (unitdp != null) {
@@ -8269,7 +8212,6 @@ public HttpResponse createReceiptAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -8414,7 +8356,6 @@ public HttpResponse createReceiptAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -8549,7 +8490,6 @@ public HttpResponse createReceiptHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -8694,7 +8634,6 @@ public HttpResponse createRepeatingInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -8841,7 +8780,6 @@ public HttpResponse createRepeatingInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -8979,7 +8917,6 @@ public HttpResponse createRepeatingInvoiceHistoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -9112,7 +9049,6 @@ public HttpResponse createRepeatingInvoicesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/RepeatingInvoices");
     if (summarizeErrors != null) {
@@ -9241,7 +9177,6 @@ public HttpResponse createTaxRatesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/TaxRates");
     String url = uriBuilder.build().toString();
@@ -9359,7 +9294,6 @@ public HttpResponse createTrackingCategoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/TrackingCategories");
     String url = uriBuilder.build().toString();
@@ -9485,7 +9419,6 @@ public HttpResponse createTrackingOptionsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -9711,7 +9644,6 @@ public HttpResponse deleteBatchPaymentForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/BatchPayments");
     String url = uriBuilder.build().toString();
@@ -9831,7 +9763,6 @@ public HttpResponse deleteBatchPaymentByUrlParamForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -10522,7 +10453,6 @@ public HttpResponse deletePaymentForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -10948,7 +10878,6 @@ public HttpResponse emailInvoiceForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -26601,7 +26530,6 @@ public HttpResponse postSetupForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Setup");
     String url = uriBuilder.build().toString();
@@ -26727,7 +26655,6 @@ public HttpResponse updateAccountForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -26862,7 +26789,6 @@ public HttpResponse updateAccountAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27005,7 +26931,6 @@ public HttpResponse updateAccountAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27149,7 +27074,6 @@ public HttpResponse updateBankTransactionForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27312,7 +27236,6 @@ public HttpResponse updateBankTransactionAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27457,7 +27380,6 @@ public HttpResponse updateBankTransactionAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27595,7 +27517,6 @@ public HttpResponse updateBankTransferAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27737,7 +27658,6 @@ public HttpResponse updateBankTransferAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27868,7 +27788,6 @@ public HttpResponse updateContactForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -27999,7 +27918,6 @@ public HttpResponse updateContactAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -28138,7 +28056,6 @@ public HttpResponse updateContactAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -28269,7 +28186,6 @@ public HttpResponse updateContactGroupForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -28404,7 +28320,6 @@ public HttpResponse updateCreditNoteForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -28563,7 +28478,6 @@ public HttpResponse updateCreditNoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -28709,7 +28623,6 @@ public HttpResponse updateCreditNoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -28840,7 +28753,6 @@ public HttpResponse updateExpenseClaimForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -28975,7 +28887,6 @@ public HttpResponse updateInvoiceForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -29130,7 +29041,6 @@ public HttpResponse updateInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -29273,7 +29183,6 @@ public HttpResponse updateInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -29410,7 +29319,6 @@ public HttpResponse updateItemForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -29564,7 +29472,6 @@ public HttpResponse updateLinkedTransactionForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -29695,7 +29602,6 @@ public HttpResponse updateManualJournalForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -29834,7 +29740,6 @@ public HttpResponse updateManualJournalAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -29980,7 +29885,6 @@ public HttpResponse updateManualJournalAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -30120,7 +30024,6 @@ public HttpResponse updateOrCreateBankTransactionsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/BankTransactions");
     if (summarizeErrors != null) {
@@ -30282,7 +30185,6 @@ public HttpResponse updateOrCreateContactsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Contacts");
     if (summarizeErrors != null) {
@@ -30432,7 +30334,6 @@ public HttpResponse updateOrCreateCreditNotesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/CreditNotes");
     if (summarizeErrors != null) {
@@ -30596,7 +30497,6 @@ public HttpResponse updateOrCreateEmployeesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Employees");
     if (summarizeErrors != null) {
@@ -30744,7 +30644,6 @@ public HttpResponse updateOrCreateInvoicesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Invoices");
     if (summarizeErrors != null) {
@@ -30912,7 +30811,6 @@ public HttpResponse updateOrCreateItemsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Items");
     if (summarizeErrors != null) {
@@ -31078,7 +30976,6 @@ public HttpResponse updateOrCreateManualJournalsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/ManualJournals");
     if (summarizeErrors != null) {
@@ -31224,7 +31121,6 @@ public HttpResponse updateOrCreatePurchaseOrdersForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PurchaseOrders");
     if (summarizeErrors != null) {
@@ -31366,7 +31262,6 @@ public HttpResponse updateOrCreateQuotesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Quotes");
     if (summarizeErrors != null) {
@@ -31515,7 +31410,6 @@ public HttpResponse updateOrCreateRepeatingInvoicesForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/RepeatingInvoices");
     if (summarizeErrors != null) {
@@ -31659,7 +31553,6 @@ public HttpResponse updatePurchaseOrderForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -31796,7 +31689,6 @@ public HttpResponse updatePurchaseOrderAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -31940,7 +31832,6 @@ public HttpResponse updatePurchaseOrderAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -32062,7 +31953,6 @@ public HttpResponse updateQuoteForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -32195,7 +32085,6 @@ public HttpResponse updateQuoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -32335,7 +32224,6 @@ public HttpResponse updateQuoteAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -32471,7 +32359,6 @@ public HttpResponse updateReceiptForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -32628,7 +32515,6 @@ public HttpResponse updateReceiptAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -32773,7 +32659,6 @@ public HttpResponse updateReceiptAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -32905,7 +32790,6 @@ public HttpResponse updateRepeatingInvoiceForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -33050,7 +32934,6 @@ public HttpResponse updateRepeatingInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -33197,7 +33080,6 @@ public HttpResponse updateRepeatingInvoiceAttachmentByFileNameForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/octet-stream");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -33314,7 +33196,6 @@ public HttpResponse updateTaxRateForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/TaxRates");
     String url = uriBuilder.build().toString();
@@ -33441,7 +33322,6 @@ public HttpResponse updateTrackingCategoryForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -33585,7 +33465,6 @@ public HttpResponse updateTrackingOptionsForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
diff --git a/src/main/java/com/xero/api/client/AppStoreApi.java b/src/main/java/com/xero/api/client/AppStoreApi.java
index 327d3f1f..14d7dbde 100644
--- a/src/main/java/com/xero/api/client/AppStoreApi.java
+++ b/src/main/java/com/xero/api/client/AppStoreApi.java
@@ -46,7 +46,7 @@ public class AppStoreApi {
   private ApiClient apiClient;
   private static AppStoreApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(AppStoreApi.class);
 
   /** AppStoreApi */
@@ -372,7 +372,6 @@ public HttpResponse postUsageRecordsForHttpResponse(
     HttpHeaders headers = new HttpHeaders();
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -505,7 +504,6 @@ public HttpResponse putUsageRecordsForHttpResponse(
     HttpHeaders headers = new HttpHeaders();
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
diff --git a/src/main/java/com/xero/api/client/AssetApi.java b/src/main/java/com/xero/api/client/AssetApi.java
index 1291f29c..93a1646b 100644
--- a/src/main/java/com/xero/api/client/AssetApi.java
+++ b/src/main/java/com/xero/api/client/AssetApi.java
@@ -49,7 +49,7 @@ public class AssetApi {
   private ApiClient apiClient;
   private static AssetApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(AssetApi.class);
 
   /** AssetApi */
@@ -197,7 +197,6 @@ public HttpResponse createAssetForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Assets");
     String url = uriBuilder.build().toString();
@@ -307,7 +306,6 @@ public HttpResponse createAssetTypeForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/AssetTypes");
     String url = uriBuilder.build().toString();
diff --git a/src/main/java/com/xero/api/client/BankFeedsApi.java b/src/main/java/com/xero/api/client/BankFeedsApi.java
index 46531610..0545e702 100644
--- a/src/main/java/com/xero/api/client/BankFeedsApi.java
+++ b/src/main/java/com/xero/api/client/BankFeedsApi.java
@@ -48,7 +48,7 @@ public class BankFeedsApi {
   private ApiClient apiClient;
   private static BankFeedsApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(BankFeedsApi.class);
 
   /** BankFeedsApi */
@@ -204,7 +204,6 @@ public HttpResponse createFeedConnectionsForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/FeedConnections");
     String url = uriBuilder.build().toString();
@@ -329,7 +328,6 @@ public HttpResponse createStatementsForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json;application/problem+json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Statements");
     String url = uriBuilder.build().toString();
@@ -436,7 +434,6 @@ public HttpResponse deleteFeedConnectionsForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder =
         UriBuilder.fromUri(apiClient.getBasePath() + "/FeedConnections/DeleteRequests");
diff --git a/src/main/java/com/xero/api/client/FilesApi.java b/src/main/java/com/xero/api/client/FilesApi.java
index 73575da3..5fa75b05 100644
--- a/src/main/java/com/xero/api/client/FilesApi.java
+++ b/src/main/java/com/xero/api/client/FilesApi.java
@@ -54,7 +54,7 @@ public class FilesApi {
   private ApiClient apiClient;
   private static FilesApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(FilesApi.class);
 
   /** FilesApi */
@@ -211,7 +211,6 @@ public HttpResponse createFileAssociationForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -314,7 +313,6 @@ public HttpResponse createFolderForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Folders");
     String url = uriBuilder.build().toString();
@@ -1692,7 +1690,6 @@ public HttpResponse updateFileForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1802,7 +1799,6 @@ public HttpResponse updateFolderForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1931,7 +1927,6 @@ public HttpResponse uploadFileForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("multipart/form-data");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Files");
     String url = uriBuilder.build().toString();
@@ -2089,7 +2084,6 @@ public HttpResponse uploadFileToFolderForHttpResponse(
     headers.set("xero-tenant-id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("multipart/form-data");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
diff --git a/src/main/java/com/xero/api/client/FinanceApi.java b/src/main/java/com/xero/api/client/FinanceApi.java
index d091900e..1bdcb407 100644
--- a/src/main/java/com/xero/api/client/FinanceApi.java
+++ b/src/main/java/com/xero/api/client/FinanceApi.java
@@ -53,7 +53,7 @@ public class FinanceApi {
   private ApiClient apiClient;
   private static FinanceApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(FinanceApi.class);
 
   /** FinanceApi */
diff --git a/src/main/java/com/xero/api/client/IdentityApi.java b/src/main/java/com/xero/api/client/IdentityApi.java
index 36c4d789..e41a84b5 100644
--- a/src/main/java/com/xero/api/client/IdentityApi.java
+++ b/src/main/java/com/xero/api/client/IdentityApi.java
@@ -45,7 +45,7 @@ public class IdentityApi {
   private ApiClient apiClient;
   private static IdentityApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(IdentityApi.class);
 
   /** IdentityApi */
diff --git a/src/main/java/com/xero/api/client/PayrollAuApi.java b/src/main/java/com/xero/api/client/PayrollAuApi.java
index 848950e8..642ab965 100644
--- a/src/main/java/com/xero/api/client/PayrollAuApi.java
+++ b/src/main/java/com/xero/api/client/PayrollAuApi.java
@@ -65,7 +65,7 @@ public class PayrollAuApi {
   private ApiClient apiClient;
   private static PayrollAuApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(PayrollAuApi.class);
 
   /** PayrollAuApi */
@@ -321,7 +321,6 @@ public HttpResponse createEmployeeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Employees");
     String url = uriBuilder.build().toString();
@@ -440,7 +439,6 @@ public HttpResponse createLeaveApplicationForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/LeaveApplications");
     String url = uriBuilder.build().toString();
@@ -538,7 +536,6 @@ public HttpResponse createPayItemForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PayItems");
     String url = uriBuilder.build().toString();
@@ -649,7 +646,6 @@ public HttpResponse createPayRunForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PayRuns");
     String url = uriBuilder.build().toString();
@@ -768,7 +764,6 @@ public HttpResponse createPayrollCalendarForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PayrollCalendars");
     String url = uriBuilder.build().toString();
@@ -879,7 +874,6 @@ public HttpResponse createSuperfundForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Superfunds");
     String url = uriBuilder.build().toString();
@@ -990,7 +984,6 @@ public HttpResponse createTimesheetForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Timesheets");
     String url = uriBuilder.build().toString();
@@ -3350,7 +3343,6 @@ public HttpResponse updateEmployeeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3468,7 +3460,6 @@ public HttpResponse updateLeaveApplicationForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3581,7 +3572,6 @@ public HttpResponse updatePayRunForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3702,7 +3692,6 @@ public HttpResponse updatePayslipForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3815,7 +3804,6 @@ public HttpResponse updateSuperfundForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -3929,7 +3917,6 @@ public HttpResponse updateTimesheetForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
diff --git a/src/main/java/com/xero/api/client/PayrollNzApi.java b/src/main/java/com/xero/api/client/PayrollNzApi.java
index 5297bad4..1d4030c9 100644
--- a/src/main/java/com/xero/api/client/PayrollNzApi.java
+++ b/src/main/java/com/xero/api/client/PayrollNzApi.java
@@ -109,7 +109,7 @@ public class PayrollNzApi {
   private ApiClient apiClient;
   private static PayrollNzApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(PayrollNzApi.class);
 
   /** PayrollNzApi */
@@ -363,7 +363,6 @@ public HttpResponse createDeductionForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Deductions");
     String url = uriBuilder.build().toString();
@@ -469,7 +468,6 @@ public HttpResponse createEarningsRateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/EarningsRates");
     String url = uriBuilder.build().toString();
@@ -573,7 +571,6 @@ public HttpResponse createEmployeeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Employees");
     String url = uriBuilder.build().toString();
@@ -700,7 +697,6 @@ public HttpResponse createEmployeeEarningsTemplateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -827,7 +823,6 @@ public HttpResponse createEmployeeLeaveForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -958,7 +953,6 @@ public HttpResponse createEmployeeLeaveSetupForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1087,7 +1081,6 @@ public HttpResponse createEmployeeLeaveTypeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1218,7 +1211,6 @@ public HttpResponse createEmployeeOpeningBalancesForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1345,7 +1337,6 @@ public HttpResponse createEmployeePaymentMethodForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1472,7 +1463,6 @@ public HttpResponse createEmployeeSalaryAndWageForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1611,7 +1601,6 @@ public HttpResponse createEmployeeWorkingPatternForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1736,7 +1725,6 @@ public HttpResponse createEmploymentForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1846,7 +1834,6 @@ public HttpResponse createLeaveTypeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/LeaveTypes");
     String url = uriBuilder.build().toString();
@@ -1973,7 +1960,6 @@ public HttpResponse createMultipleEmployeeEarningsTemplateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2082,7 +2068,6 @@ public HttpResponse createPayRunForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PayRuns");
     String url = uriBuilder.build().toString();
@@ -2189,7 +2174,6 @@ public HttpResponse createPayRunCalendarForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PayRunCalendars");
     String url = uriBuilder.build().toString();
@@ -2296,7 +2280,6 @@ public HttpResponse createReimbursementForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Reimbursements");
     String url = uriBuilder.build().toString();
@@ -2402,7 +2385,6 @@ public HttpResponse createSuperannuationForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Superannuations");
     String url = uriBuilder.build().toString();
@@ -2507,7 +2489,6 @@ public HttpResponse createTimesheetForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Timesheets");
     String url = uriBuilder.build().toString();
@@ -2628,7 +2609,6 @@ public HttpResponse createTimesheetLineForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7375,7 +7355,6 @@ public HttpResponse updateEmployeeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7520,7 +7499,6 @@ public HttpResponse updateEmployeeEarningsTemplateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7657,7 +7635,6 @@ public HttpResponse updateEmployeeLeaveForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7799,7 +7776,6 @@ public HttpResponse updateEmployeeSalaryAndWageForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7922,7 +7898,6 @@ public HttpResponse updateEmployeeTaxForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -8046,7 +8021,6 @@ public HttpResponse updatePaySlipLineItemsForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -8184,7 +8158,6 @@ public HttpResponse updateTimesheetLineForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
diff --git a/src/main/java/com/xero/api/client/PayrollUkApi.java b/src/main/java/com/xero/api/client/PayrollUkApi.java
index cb941558..ed4fa150 100644
--- a/src/main/java/com/xero/api/client/PayrollUkApi.java
+++ b/src/main/java/com/xero/api/client/PayrollUkApi.java
@@ -105,7 +105,7 @@ public class PayrollUkApi {
   private ApiClient apiClient;
   private static PayrollUkApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(PayrollUkApi.class);
 
   /** PayrollUkApi */
@@ -358,7 +358,6 @@ public HttpResponse createBenefitForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Benefits");
     String url = uriBuilder.build().toString();
@@ -463,7 +462,6 @@ public HttpResponse createDeductionForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Deductions");
     String url = uriBuilder.build().toString();
@@ -569,7 +567,6 @@ public HttpResponse createEarningsRateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/EarningsRates");
     String url = uriBuilder.build().toString();
@@ -673,7 +670,6 @@ public HttpResponse createEmployeeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Employees");
     String url = uriBuilder.build().toString();
@@ -800,7 +796,6 @@ public HttpResponse createEmployeeEarningsTemplateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -927,7 +922,6 @@ public HttpResponse createEmployeeLeaveForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1056,7 +1050,6 @@ public HttpResponse createEmployeeLeaveTypeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1187,7 +1180,6 @@ public HttpResponse createEmployeeOpeningBalancesForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1314,7 +1306,6 @@ public HttpResponse createEmployeePaymentMethodForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1441,7 +1432,6 @@ public HttpResponse createEmployeeSalaryAndWageForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1564,7 +1554,6 @@ public HttpResponse createEmployeeStatutorySickLeaveForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/StatutoryLeaves/Sick");
     String url = uriBuilder.build().toString();
@@ -1684,7 +1673,6 @@ public HttpResponse createEmploymentForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1794,7 +1782,6 @@ public HttpResponse createLeaveTypeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/LeaveTypes");
     String url = uriBuilder.build().toString();
@@ -1919,7 +1906,6 @@ public HttpResponse createMultipleEmployeeEarningsTemplateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2031,7 +2017,6 @@ public HttpResponse createPayRunCalendarForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/PayRunCalendars");
     String url = uriBuilder.build().toString();
@@ -2138,7 +2123,6 @@ public HttpResponse createReimbursementForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Reimbursements");
     String url = uriBuilder.build().toString();
@@ -2243,7 +2227,6 @@ public HttpResponse createTimesheetForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Timesheets");
     String url = uriBuilder.build().toString();
@@ -2364,7 +2347,6 @@ public HttpResponse createTimesheetLineForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7290,7 +7272,6 @@ public HttpResponse updateEmployeeForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7435,7 +7416,6 @@ public HttpResponse updateEmployeeEarningsTemplateForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7572,7 +7552,6 @@ public HttpResponse updateEmployeeLeaveForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7704,7 +7683,6 @@ public HttpResponse updateEmployeeOpeningBalancesForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7845,7 +7823,6 @@ public HttpResponse updateEmployeeSalaryAndWageForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -7986,7 +7963,6 @@ public HttpResponse updateTimesheetLineForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
diff --git a/src/main/java/com/xero/api/client/ProjectApi.java b/src/main/java/com/xero/api/client/ProjectApi.java
index 7f35ff46..0df04c75 100644
--- a/src/main/java/com/xero/api/client/ProjectApi.java
+++ b/src/main/java/com/xero/api/client/ProjectApi.java
@@ -57,7 +57,7 @@ public class ProjectApi {
   private ApiClient apiClient;
   private static ProjectApi instance = null;
   private String userAgent = "Default";
-  private String version = "12.3.0";
+  private String version = "12.3.1";
   static final Logger logger = LoggerFactory.getLogger(ProjectApi.class);
 
   /** ProjectApi */
@@ -204,7 +204,6 @@ public HttpResponse createProjectForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     UriBuilder uriBuilder = UriBuilder.fromUri(apiClient.getBasePath() + "/Projects");
     String url = uriBuilder.build().toString();
@@ -317,7 +316,6 @@ public HttpResponse createTaskForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -437,7 +435,6 @@ public HttpResponse createTimeEntryForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -1963,7 +1960,6 @@ public HttpResponse patchProjectForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2077,7 +2073,6 @@ public HttpResponse updateProjectForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2199,7 +2194,6 @@ public HttpResponse updateTaskForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();
@@ -2328,7 +2322,6 @@ public HttpResponse updateTimeEntryForHttpResponse(
     headers.set("Xero-Tenant-Id", xeroTenantId);
     headers.set("Idempotency-Key", idempotencyKey);
     headers.setAccept("application/json");
-    headers.setContentType("application/json");
     headers.setUserAgent(this.getUserAgent());
     // create a map of path variables
     final Map<String, Object> uriVariables = new HashMap<String, Object>();