Process invoices and send weekly AI reports with OpenAI and Gmail

Overview

This workflow automates invoice handling from upload to reporting using AI.

Users submit invoices through a simple form. The workflow extracts key details, validates the data, stores valid invoices, and sends email notifications. It also generates a weekly summary report automatically.

This helps reduce manual data entry and ensures consistent invoice processing.

How It Works

1. Form Submission
   Users upload an invoice (PDF or image) along with their email.

2. Initial Storage
   The raw submission is stored for tracking and reference.

3. Text Extraction
   The uploaded file is processed to extract text content.

4. AI Data Extraction
   AI converts the raw text into structured invoice data such as invoice number, vendor, date, currency, and totals.

5. Validation
   The workflow checks:

   • Date format (YYYY-MM-DD)
   • Allowed currencies
   • Total amount validity

6. Conditional Flow

   • If valid → invoice is stored and a success email is sent
   • If invalid → an error email is sent with details

7. Weekly Reporting
   A scheduled trigger runs weekly to:

   • Fetch all validated invoices
   • Generate a summary report using AI
   • Send the report via email

Setup Instructions

1. Add your OpenAI credentials (used for data extraction and reporting)
2. Connect Gmail credentials for sending emails
3. Configure Data Tables:
   • invoice_form_submissions
   • validated_invoices
4. Update the Workflow Configuration node:
   • Set report recipient email
   • Adjust allowed currencies if needed
5. Ensure the file field (invoiceFile) is correctly mapped
6. Test with a sample invoice
7. Activate the workflow

Use Cases

• Automating invoice processing for small businesses
• Reducing manual accounting data entry
• Validating invoices before storing them
• Generating weekly financial summaries
• Handling invoice submissions from clients or teams

Requirements

• OpenAI API credentials
• Gmail account (for sending emails)
• n8n Data Tables (or replace with your preferred database)
• n8n instance with file upload support

Notes

• Make sure to fix the IF condition:
  Use {{$json.validation.isValid}} instead of accessing isValid directly.

• You can extend validation rules in the Code node based on your business needs.

• The reporting section can be customized to include more insights or formats.