Gmail Invoice PDF Extractor to Google Sheets CRM (n8n)

Automatically Extract Invoice Data from Gmail PDFs into Google Sheets (n8n)

This n8n workflow polls your Gmail for new invoice emails, extracts text from attached PDFs, uses OpenRouter to convert the invoice into structured fields, and appends the results to your Google Sheets Invoice tab—while sending anything unprocessable to a Review tab.

What this workflow does

• Polls Gmail every minute for new emails and downloads attachments.
• Processes multiple attachments per email by splitting each email into one item per attachment (so multiple invoices are handled separately).
• Routes non-PDF attachments directly to a Google Sheets Review tab.
• Extracts text from each PDF attachment.
• Detects unreadable/scanned PDFs (no extracted text, e.g., image-only) and routes those files to the Review tab for manual handling.
• Parses invoice fields with OpenRouter by sending the extracted invoice text to a chat model and structuring key outputs such as vendor, invoice number, dates, and totals.
• Appends records to Google Sheets with added metadata, including received date, source email address, and a “New” status.

Use cases

• Accounts teams who receive invoices by email and want automatic invoice line ingestion into a Google Sheets CRM.
• SaaS operators who centralize invoice tracking without building a full custom system—using an n8n Gmail → Google Sheets pipeline.
• Teams handling mixed attachments where non-PDFs or scanned documents should be flagged for review instead of blocking automation.

Technical details

• n8n Gmail Trigger (OAuth2): monitors your selected mailbox/filters and polls every minute.
• Google Sheets actions: appends to Invoice and Review tabs.
• OpenRouter node: parses extracted invoice text into structured fields.
• Core workflow nodes: if, set, code, and supporting logic for attachment splitting and routing.

Includes a practical review path for non-PDF and textless PDFs, so your Google Sheets stays accurate while you handle exceptions.