AI Invoice Automation System - Extract, Validate & Archive Invoices with 99% Accuracy

A complete, production-ready n8n workflow that automatically:

✅ Extracts invoice data from photos (Telegram)

✅ Validates totals with 99% accuracy using GPT-API

✅ Archives files to Google Drive (organized by category)

✅ Logs everything to Google Sheets (invoices + line items)

✅ Sends you detailed success/error notifications

✅ Generates weekly analytics reports

✅ Includes audit trail for compliance

? Perfect For

Small Business Owners drowning in paper invoices

Accountants & Bookkeepers managing multiple clients

Freelancers who need simple expense tracking

Operations Managers automating AP workflows

Anyone who receives invoices via email/messaging

? Key Features

? Security & Access Control

User whitelist authentication

Rate limiting (50/hour, 500/day)

File size validation (10MB max)

Transaction ID tracking

? AI-Powered Extraction

Uses OpenAI GPT-API for maximum accuracy

Extracts: vendor, invoice #, date, total, tax, line items

Smart category detection (Finance/Maintenance/Retail)

Confidence scoring for quality assurance

✅ Data Validation

Automatic integrity checks (totals vs line items)

Duplicate detection

Input sanitization (prevents errors)

Quality scoring (0-100)

? Comprehensive Tracking

Google Sheets integration (2 sheets: Invoices + Items)

Audit log for compliance

Processing metrics (time, confidence, quality)

Weekly analytics reports via Telegram

? User Experience

Real-time Telegram notifications

Detailed success/error messages

Progress updates during processing

Rich formatting with emojis

? What You'll Save

Before:

⏱️ 5-10 minutes per invoice

? Manual data entry errors

? Messy file organization

? No searchable database

After:

⚡ 30 seconds per invoice (automated)

✅ 99% accuracy with AI validation

?️ Auto-organized by category

? Instant reporting & analytics

ROI: If you process just 10 invoices/week, you'll save 8+ hours per month