Gmail Invoice Automation in n8n: Drive Save + PDF.co Extract

Automatically save Gmail invoice PDFs, extract totals with Claude, and log everything to Google Sheets

This Gmail Invoice Automation in n8n watches your inbox for invoice/receipt emails, stores the PDFs in a clean Google Drive YYYY/YYYY-MM folder structure, uses Anthropic Claude to extract key invoice fields, and appends them to a monthly Invoices YYYY-MM Google Sheets file—then labels each processed email so it won’t run twice.

What this workflow does

• Checks Gmail every 15 minutes for messages matching your invoice/receipt search and not yet labeled invoices-processed.
• Downloads attachments on matching emails.
• Determines the filing period from the email date (with an option to file to the previous month).
• Detects invoice links inside the email body (when applicable).
• Finds or creates Drive folders: a year folder (YYYY) and a month folder (YYYY-MM) under your chosen root invoices folder.
• Gets the PDF from attachments, or retrieves/produces a PDF from the detected invoice source using PDF.co.
• Extracts invoice data by sending each invoice PDF to Anthropic Claude to extract: supplier name, VAT/tax ID, issue date, amount, and currency.
• Uploads and logs: saves the PDF to the month folder and appends a row to the matching Invoices YYYY-MM Google Sheets file (creating/moving the sheet within the month folder if needed).
• Prevents reprocessing by adding the invoices-processed label to the Gmail message.

Use cases

• SaaS operators consolidating invoice documentation for monthly accounting.
• Automation engineers building a reliable inbox-to-Drive invoice archive with structured reporting.
• Teams wanting automatic PDF storage plus extracted totals (amount, currency, VAT/tax ID) in Google Sheets.

Technical details

• Trigger: periodic run every 15 minutes from Gmail (invoice/receipt search, label check).
• Core logic: if, set, code, and no op nodes for routing and data handling.
• PDF handling: PDF.co for PDF generation from invoice links (when needed).
• AI extraction: Anthropic Claude for structured invoice field extraction.
• Storage & reporting: Google Drive (YYYY/YYYY-MM folders) and monthly Google Sheets.
• Setup requirement: create/select a Gmail label named invoices-processed, connect Gmail OAuth2 and Google Drive.