How to Automate Expense Reimbursement with n8n and Receipt Parser API

Target keywords: n8n receipt automation, automate expense reimbursement workflow, n8n HTTP node API

Platform: dev.to (primary) + n8n Community Discord #showcase + Hashnode (cross-post)

Word count target: 1,200–1,500 words

Meta title (60 chars): Automate Expense Reimbursement with n8n + Receipt API

Meta description (155 chars): Build an n8n workflow that parses receipt images, extracts structured data, and routes them for approval — no code required. Step-by-step tutorial.

The API powering this workflow — try it before you build:

👉 ilovesreceipt.com

Upload any receipt and see the structured JSON output in seconds.

What We're Building

An n8n workflow that:

1. 
   Triggers when a receipt image is submitted (email attachment, Google Drive upload, or webhook)


2. 
   Parses the receipt using the Receipt Parser API → returns structured JSON


3. 
   Routes based on amount: auto-approves small expenses, flags large ones for manager review


4. 
   Logs every expense to a Google Sheet


5. 
   Notifies the submitter via Slack or email with the parsed details

No code required. Pure n8n nodes.

Prerequisites

• n8n instance (cloud or self-hosted — n8n.io)


• Receipt Parser API key from ilovesreceipt.com (free tier: 500 calls/month)


• Google account (for Sheets logging)


• Optional: Slack workspace for notifications

Workflow Overview

[Trigger] → [HTTP Request: Parse Receipt] → [IF: Amount > $50?]

                                                 ├── YES → [Slack: Flag for Review]

                                                 └── NO  → [Google Sheets: Log Expense]

                                                                    ↓

                                               [Gmail/Slack: Notify Submitter]

Step 1: Set Up the Trigger

Choose your entry point based on how employees submit receipts:

Option A — Webhook (most flexible):

Add a Webhook node. Set method to POST. This lets you trigger the workflow from any tool (form, mobile app, Zapier) that can send a webhook.

Option B — Gmail (receipts by email):

Add a Gmail Trigger node. Filter by subject containing "receipt" or "reimbursement". The workflow fires each time a matching email arrives with an attachment.

Option C — Google Drive:

Add a Google Drive Trigger node. Watch a specific folder (e.g., /Receipts/Pending). Fires when any new file is uploaded.

For this tutorial we'll use the Webhook option since it's the most reusable.

Step 2: Read the File

No conversion needed. The Receipt Parser API accepts the raw file directly as multipart/form-data — no base64 encoding required.

If your trigger provides a URL (e.g. a Google Drive file URL), add an HTTP Request node set to GET to download the binary first. If your trigger provides a binary attachment directly (e.g. Gmail attachment), pipe it straight into Step 3.

Step 3: Call the Receipt Parser API

Add an HTTP Request node with these settings:

Tip: Store your API key in n8n Credentials as a Generic Credential with Authorization → Bearer YOUR_KEY. This keeps it secure and reusable across workflows. Get your free key at ilovesreceipt.com — 500 calls/month, no credit card required.

After this node runs, you'll have the full parsed JSON available in subsequent nodes as $json.data.merchant.name, $json.data.total, etc.

Step 4: Add Routing Logic (IF Node)

Add an IF node to route based on the expense amount:

Condition:

{{ $json.data.total }} > 50

• 
  True branch → flag for manager review (high expense)


• 
  False branch → auto-approve and log

You can layer additional conditions:

• Category-based routing (meals vs. travel vs. supplies)


• Merchant allowlist/blocklist


• Employee-specific thresholds

Step 5: Log to Google Sheets

On the False (auto-approved) branch, add a Google Sheets node:

• Operation: Append Row
  


• Spreadsheet: your expense log sheet


• Sheet: Expenses
  

Map these columns:

Step 6: Flag for Manager Review (Slack)

On the True (high expense) branch, add a Slack node:

• Operation: Send Message


• Channel: #expense-approvals
  


• Message:
  

🧾 *Expense Approval Required*



*Merchant:* {{ $json.data.merchant.name }}

*Amount:* ${{ $json.data.total }}

*Date:* {{ $json.data.date }}

*Payment:* {{ $json.data.payment_method }}



React ✅ to approve or ❌ to reject.

Step 7: Notify the Submitter

On both branches, add a Gmail or Slack node to confirm receipt:

Hi there — your expense was received and parsed successfully.



Merchant: {{ $json.data.merchant.name }}

Date: {{ $json.data.date }}

Total: ${{ $json.data.total }}



{{ $json.data.total > 50 ? "Your expense has been flagged for manager review." : "Your expense has been auto-approved and logged." }}

The Complete Workflow (JSON Import)

You can import this workflow directly into n8n. Copy the JSON below and use File → Import from JSON in n8n:

Download workflow JSON ← (link to GitHub gist with the workflow JSON)

Testing the Workflow

1. Open the workflow in n8n


2. Click Execute Workflow with test mode on


3. Send a POST request to your webhook URL with a receipt image:
   

curl -X POST https://your-n8n-instance.com/webhook/receipt-parse \

  -F "[email protected]"

1. Check your Google Sheet for the logged row and Slack for any approval notifications.

Going Further

• 
  Multi-currency support: The API detects currency — add a conversion step using an exchange rate API


• 
  PDF invoices: The API handles PDFs too — great for contractor invoices submitted via email attachment


• 
  Airtable instead of Sheets: Swap the Google Sheets node for an Airtable node for richer filtering


• 
  Approval loop: Use n8n's Wait node to pause the workflow until a Slack reaction is received

Try the API First

Before building the workflow, see what the parsed JSON looks like for your receipt types:

👉 Live Demo — no signup required

Ready to start building? Get your free API key at ilovesreceipt.com — 500 calls/month, no credit card required.

Built this workflow or have a question about a specific node? Share it in the comments — I'll help debug.