n8n Expense Receipt Automation: Gmail + Telegram to Notion

Automatically log your receipts from Gmail and Telegram into Notion—no manual data entry

This n8n Expense Receipt Automation workflow reads receipt attachments from Gmail and receipt photos from Telegram, extracts structured expense fields using OpenAI (gpt-4o-mini), and creates a new expense entry in your Notion database—then sends a Telegram confirmation. If anything goes wrong, it alerts you via Slack and Telegram.

What this workflow does

• Gmail receipt intake: Triggers on a new Gmail message that matches your receipt search filter and includes an attachment.
• Attachment handling: Grabs the first email attachment, detects whether it’s a PDF, and extracts PDF text when applicable.
• Receipt extraction with OpenAI: Sends either the PDF text or the receipt image content to OpenAI (gpt-4o-mini) to return receipt data as JSON (vendor, date, amount, currency, category, summary).
• Telegram receipt photo intake: Triggers on a new Telegram message and continues only if the message includes a photo.
• Image preparation: Downloads the highest-resolution Telegram photo, converts it to a base64 data URL, and sends it to OpenAI for JSON extraction.
• Notion logging: Parses the OpenAI response into normalized fields and creates a new page in your Notion expenses database.
• Confirmation + error alerts: Sends a Telegram message confirming the logged expense; on workflow errors, posts alerts to Slack and Telegram.

Use cases

• Expense tracking for SaaS operators: automatically capture receipts sent to Gmail or submitted in Telegram.
• Freelancers and teams: centralize vendor/date/amount/category in Notion without copying from PDFs or images.
• Automation engineers: a practical n8n pattern for Gmail + Telegram ingestion, OpenAI extraction, and Notion persistence.

Technical details

• Nodes/stack: if, code, no op, slack, notion, telegram
• Integrations: Gmail OAuth2, Telegram Bot API, OpenAI, Notion, and Slack OAuth2 (for error alerts)
• Setup requirement: Set REPLACE_WITH_YOUR_NOTION_EXPENSES_DATABASE_ID and ensure the database has matching properties (Vendor, Amount, Currency, Date, Category, Source, Notes).