Receipt Processing Automation

A webhook-triggered n8n workflow that automatically processes expense receipts from Airtable: downloads attachments, converts images to PDF, uploads to Dropbox, and updates record status - all with comprehensive error handling and notifications.

What This Does

When a new expense is added to Airtable (or an existing expense is marked for processing), Airtable sends a webhook to n8n. This workflow automatically:

1. Retrieves the expense record and attachment from Airtable
2. Downloads the receipt file
3. Converts images (JPG/PNG) to PDF using CloudConvert
4. Uploads the PDF to Dropbox with a structured filename
5. Updates the Airtable record to mark it as processed
6. Sends email notifications if any step fails

Perfect for businesses tracking expenses, consultants managing client receipts, or teams needing organized receipt archiving.

Key Features

• Webhook-Triggered: Instant processing when expenses are added
• Smart File Handling: Converts images to PDF, passes through existing PDFs unchanged
• Organized Storage: Files saved with consistent naming: ExpenseName YYYYMMDD.pdf
• Comprehensive Error Handling: Email notifications at every failure point
• Idempotent: Safe to retry - won't duplicate files or break on re-runs
• Status Tracking: Updates Airtable fields to track processing state

Use Cases

• Automated expense receipt archiving for accounting/tax purposes
• Client reimbursement documentation management
• Receipt collection for credit card reconciliation
• Automated backup of financial documents to cloud storage

Data Flow

Airtable Automation triggers webhook
  → n8n receives webhook with record ID
  → Fetch Airtable record
  → Download receipt attachment
  → Check file type
    ├─ Image (jpg/png): Convert to PDF via CloudConvert
    └─ Already PDF: Skip conversion
  → Upload to Dropbox with structured filename
  → Update Airtable record status
  → Send success/failure notifications

Architecture Overview

This workflow demonstrates several production patterns:

• Graceful degradation: Each step validates success before proceeding
• Error isolation: Failures at any step trigger specific notifications
• Atomic operations: Dropbox upload and Airtable update are independent
• Clear audit trail: Email notifications provide complete failure context

Airtable Setup

Required Fields

Your Airtable Expenses table needs these fields:

Field Name	Type	Description
Expense Name	Single line text	Description of the expense
Date	Date	When expense occurred
Amount	Currency	Expense amount
Category	Single select	Expense category
Receipt	Attachment	The receipt file (image or PDF)
Submitted	Checkbox	Marks expense as ready for processing
Synced to Dropbox	Checkbox	Workflow sets this when complete

Airtable Automation Setup

Create an Airtable automation:

Trigger: When record matches conditions

• Conditions: Submitted = checked AND Synced to Dropbox = unchecked

Action: Send webhook

• URL: https://your-n8n-instance.com/webhook/airtable-receipt
• Method: POST
• Body:

{
  "recordId": "AIRTABLE_RECORD_ID()"
}

Replace your-n8n-instance.com with your actual n8n webhook URL (found in the Webhook node after importing).

n8n Setup

1. Prerequisites

• n8n instance (cloud or self-hosted)
• Airtable Personal Access Token
• Dropbox OAuth2 credentials
• CloudConvert API account (free tier available)
• Gmail OAuth2 for notifications (or another email service)

2. Import the Workflow

1. Download workflow.json from this repository
2. In n8n: Import from File
3. Select the downloaded JSON

3. Configure Credentials

Replace placeholder credential IDs:

Airtable Personal Access Token (YOUR_AIRTABLE_CREDENTIAL_ID)

• Scopes needed: data.records:read, data.records:write, schema.bases:read
• Used in: Get Airtable record, Update Airtable record

Dropbox OAuth2 (YOUR_DROPBOX_CREDENTIAL_ID)

• Scopes needed: files.content.write
• Used in: Add file to Dropbox

CloudConvert OAuth2 (YOUR_CLOUDCONVERT_CREDENTIAL_ID)

• Used in: CloudConvert node
• Free tier: 25 conversions/day

Gmail OAuth2 (YOUR_GMAIL_CREDENTIAL_ID)

• Used in: All notification nodes
• Alternative: Replace with email service of choice (SendGrid, Mailgun, etc.)

4. Configure Airtable Base & Table

Replace these placeholders:

• YOUR_AIRTABLE_BASE_ID - Your base ID (starts with app...)
• YOUR_AIRTABLE_TABLE_ID - Your table ID (starts with tbl...)

Finding IDs: Airtable Help → API Documentation → locate IDs in the docs

5. Configure Dropbox Path

In the "Add file to Dropbox" node, update the path:

path: "=/Receipts/{{ $('Get Airtable record').item.json['Expense Name'] }} {{ DateTime.fromISO($('Get Airtable record').item.json.Date).toFormat('yyyyMMdd') }}.pdf"

Change /Receipts/ to your desired Dropbox folder path.

6. Configure Email Notifications

Replace YOUR_EMAIL@example.com in all Gmail notification nodes with your actual email address.

Notification types:

• Invalid webhook data
• Download failure
• Conversion failure
• Upload failure
• Airtable update failure

7. Get Webhook URL

1. Open the Webhook node
2. Copy the Production URL
3. Use this URL in your Airtable automation

8. Test the Workflow

1. Add a test expense in Airtable with a receipt attachment
2. Check the Submitted checkbox
3. Monitor n8n execution log
4. Verify:
   • File appears in Dropbox
   • Synced to Dropbox is checked in Airtable
   • No error emails received

9. Activate

Click Active toggle in n8n - workflow is now live.

File Naming Convention

Files are saved to Dropbox with this format:

ExpenseName YYYYMMDD.pdf

Examples:

• Office Supplies 20240115.pdf
• Client Lunch 20240120.pdf
• Software Subscription 20240201.pdf

This ensures:

• Chronological sorting
• Human-readable names
• No duplicate filenames (Date + Expense Name is unique)

Customization Options

Support Additional File Types

To handle more image formats, modify the "Is Image (jpg/png)?" condition:

conditions: [
  { "leftValue": "={{ $json.Receipt[0].type }}", "rightValue": "image/jpeg" },
  { "leftValue": "={{ $json.Receipt[0].type }}", "rightValue": "image/png" },
  { "leftValue": "={{ $json.Receipt[0].type }}", "rightValue": "image/webp" }  // Add this
]

CloudConvert supports: jpg, png, gif, bmp, webp, tiff, and many more.

Change Dropbox Folder Structure

Organize by month, client, or category:

// By month
path: "=/Receipts/{{ DateTime.fromISO($('Get Airtable record').item.json.Date).toFormat('yyyy-MM') }}/{{ ... }}"

// By category
path: "=/Receipts/{{ $('Get Airtable record').item.json.Category }}/{{ ... }}"

// By client (if you have a Client field)
path: "=/Receipts/{{ $('Get Airtable record').item.json.Client }}/{{ ... }}"

Use Different Cloud Storage

Replace the Dropbox node with:

• Google Drive: Use Google Drive node
• OneDrive: Use Microsoft OneDrive node
• S3: Use AWS S3 node
• SFTP: Use FTP node for self-hosted storage

Alternative to CloudConvert

CloudConvert has usage limits on the free tier. Alternatives:

ImageMagick (self-hosted n8n only):

• Install ImageMagick on your n8n server
• Replace CloudConvert node with Execute Command node:

convert input.jpg -quality 100 output.pdf

Python script (self-hosted):

• Use n8n's Code node with Python
• Libraries: PIL (Pillow), img2pdf

Batch Processing

To process multiple unsynced expenses at once:

1. Replace Webhook trigger with Schedule Trigger
2. Add Airtable Search node: Find records where Submitted = checked AND Synced to Dropbox = unchecked
3. Loop through results

This is useful for bulk backfills or if the webhook misses records.

Error Handling Details

The workflow includes 5 error notification points:

Failure Point	Email Subject	Likely Cause
Invalid webhook	Invalid Webhook Data	Airtable automation misconfigured
Record not found	Receipt Download Failed	Record deleted before processing
Download failed	Receipt Download Failed	Attachment URL expired or invalid
Conversion failed	Image Conversion Failed	CloudConvert service down or quota exceeded
Upload failed	Dropbox Upload Failed	Dropbox authentication expired or storage full
Update failed	Airtable Update Failed	Airtable token expired (file uploaded successfully)

Each email includes:

• Record ID
• Expense Name
• Date
• Specific failure context

This makes manual intervention straightforward when issues occur.

Troubleshooting

Webhook not triggering:

• Verify webhook URL is correct in Airtable automation
• Check n8n webhook node is active
• Test webhook manually with Postman/curl

CloudConvert quota exceeded:

• CloudConvert free tier: 25 conversions/day
• Upgrade account or implement daily batch processing
• Alternative: Use ImageMagick for unlimited conversions (self-hosted)

Dropbox upload fails with "invalid path":

• Check Dropbox folder exists
• Ensure Expense Name doesn't contain illegal characters (/, \, :, *, ?, ", <, >, |)
• Add sanitization in the path expression if needed

Airtable update fails after successful upload:

• File is in Dropbox but record not marked complete
• Check Airtable token permissions
• Manually update record and investigate token expiry

Duplicate files in Dropbox:

• Workflow uses file naming based on Expense Name + Date
• If same expense + date combination exists, Dropbox will append (1), (2), etc.
• Ensure Expense Name + Date combination is unique per receipt

Production Best Practices

1. Monitor error emails daily - Set up email filters/labels for quick review
2. Test with all file types - JPG, PNG, PDF before going live
3. Backup Airtable regularly - Export expenses monthly as CSV backup
4. CloudConvert alternatives - Have ImageMagick ready if you hit API limits
5. Webhook security - Consider adding authentication to webhook endpoint
6. Rate limiting - Airtable automation may batch webhooks; ensure n8n can handle volume

Cost Considerations

Free tier limits:

• n8n.cloud: 5,000 workflow executions/month
• CloudConvert: 25 conversions/day
• Airtable: 50,000 records per base
• Dropbox: 2GB storage (Basic plan)

Scaling:

• Self-host n8n for unlimited executions
• CloudConvert paid plan: $9/month for 500 conversions
• Business Airtable for higher limits
• Dropbox Plus: 2TB storage

License

MIT - Feel free to use, modify, and distribute. Attribution appreciated but not required.

About

Created by Ken Davis at Lodgepole I/O - Workflow design and operational systems consulting.

This workflow is based on production use for expense tracking and receipt management. It processes hundreds of receipts per month reliably since 2024.

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Check out my other n8n templates:

• Email-Based Time Tracking - Automated time logging for invoicing
• More coming soon!