Telegram Expense Receipt OCR to Google Sheets with GPT-4o-mini

Turn Telegram receipt photos into approved expenses in Google Sheets—automatically

This n8n workflow listens for Telegram receipt submissions, extracts expense details using OpenAI GPT-4o-mini Vision, applies your Google Sheets policy rules, routes items for auto-approval or manager approval in Telegram, and records results back into Google Sheets—with a monthly Gmail report.

What this workflow does

• Telegram-triggered receipt intake: When a message is sent to your Telegram bot, the workflow downloads the largest attached photo.
• Receipt validation prompt: If no photo is included, it replies in Telegram asking the employee to submit the receipt as a photo.
• OCR + structured extraction with GPT-4o-mini Vision: The receipt image is sent to GPT-4o-mini Vision to extract merchant, date, total, currency, tax, category, and confidence, then normalize values for consistent processing.
• Policy + duplicate checking from Google Sheets: Loads rules from the Google Sheets Policy tab and checks the Google Sheets Expenses tab for a matching duplicate receipt key.
• Decision routing: Auto-approves within limits; flags duplicates or unreadable/missing fields; rejects non-allowed/over-limit categories; or requests manager approval for out-of-policy, low-confidence, or old receipts.
• Manager review in Telegram: Sends an approval request to the manager and waits up to 3 days for an approve/reject response.
• Recordkeeping + notifications: Appends the final outcome to the Google Sheets Expenses tab, replies to the employee in Telegram with the decision, and forwards approved receipt photos to a finance Telegram chat.
• Monthly reporting: On the first day of each month, it emails a monthly report via Gmail for approved expenses.

Use cases

• Expense reimbursements where employees submit receipts through Telegram
• Finance teams that want policy-based approvals with auditable Google Sheets records
• SaaS operators running n8n to standardize receipt OCR and approval workflows

Technical details

• Integrations: Telegram, Google Sheets, Gmail, OpenAI GPT-4o-mini Vision
• n8n logic/nodes used: if, set, code, no op, gmail, merge
• Output destination: Google Sheets Expenses tab + Telegram employee/manager notifications