Automate Invoice Data Extraction with Google Gemini & n8n

Transform your invoice processing from manual data entry to fully automated extraction in minutes. This powerful n8n workflow leverages Google Gemini AI to automatically extract structured data from invoice PDFs and images, then seamlessly stores the results in Google Sheets with intelligent Telegram notifications.

What this workflow does

This comprehensive automation accepts invoice files through multiple channels—either via n8n Form uploads or Telegram bot messages—and processes them with precision:

• Validates incoming files to ensure they're supported PDF or image formats
• Routes documents to Google Gemini for intelligent OCR and data extraction using document or image analysis
• Extracts structured invoice fields and line items with automatic date and numeric field normalization
• Splits line items into individual rows and appends all data to your Google Sheets Invoices worksheet
• Sends detailed processing summaries or rejection notifications via Telegram

Use cases

Perfect for businesses and automation engineers who need to:

• Automate accounts payable processing for multiple vendors and formats
• Extract invoice data for expense tracking and financial reporting
• Process supplier invoices received via email attachments or messaging apps
• Build automated invoice approval workflows with structured data extraction
• Eliminate manual data entry errors in accounting systems

Technical details

Built with essential n8n nodes including Form Trigger for web-based uploads, Telegram integration for messaging workflows, and advanced logic using If conditions, Code nodes for data processing, and Split Out nodes for handling line items. The workflow integrates seamlessly with Google Gemini (PaLM) API for AI-powered document analysis and Google Sheets OAuth2 for secure data storage.

Setup requires Google Gemini API credentials with your preferred model (like gemini-2.5-flash), Google Sheets access with a designated Invoices worksheet, and Telegram bot configuration for notifications. The flexible dual-input design supports both form-based and conversational invoice submission workflows.