Categories / Invoicing/
n8n invoice AI: owner cuts processing 15 hrs/week → 1.5; $47k overcharges caught
Invoice processing fell from 15 to 1.5 hours a week and caught $47k in vendor overcharges.
Costn8n + OpenRouter LLM + SheetsFirst-person write-up. Start with your top vendors; the >10% price-variance flag is the money-maker.
BusinessB2B operator / finance lead processing hundreds of vendor invoices weekly (first-person b2bautomator.com write-up)
StatusNew✓ Setup guide
Added2026-10-14
SourceWeb View original ↗
- Task
- OCR, price-check, and route AP invoices without late-night manual entry
- Result
- 15 hrs/week → 1.5 hrs/week (89% reduction after 6 months); 94% fewer processing errors; $47,000 identified overcharges; duplicate payments to zero
- Tools
- n8n
- OpenRouter LLM
- Google Drive
- Google Sheets master pricing
- PDF extract
- Setup
- upload PDFs to Drive → n8n extracts text → LLM structures line items → validate vs Sheets master/vendor contracts with >10% variance flags → fallback manual review → approval routing
- start with top vendors
Step-by-step setup guide + copy-paste prompt
Benefit: Vendor PDFs are parsed into line items, checked against your price list, flagged when off by more than 10%, and routed for approval.
Recipe
- Upload invoice PDFs to a Google Drive folder that n8n watches.
- Extract the text, then use an LLM (via OpenRouter) to structure the line items.
- Compare against the master price sheet and contracts; flag variances over 10% and duplicates.
- Clean invoices go to the approver; flagged ones go to manual review.
- Start with your top 5 vendors and expand once accuracy holds.
Copy-paste prompt
Structure these invoice line items as JSON [{sku, description, qty, unit_price, line_total}].
Then compare against this price list and flag any line where unit_price is more than 10% above contract.
Invoice text: {{text}}
Price list: {{csv}}Sources
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