Prípadová štúdia - AI invoice automation from Gmail

Overview

Time-saving automation: invoice attachments arriving in Gmail are automatically processed and recorded in SuperFaktura. Since SuperFaktura doesn't natively support invoice data extraction (OCR/ICR), this workflow adds an AI extraction step and removes manual data entry.

The system detects new invoice emails in Gmail, uses AI to extract key fields from attached invoices (OCR/ICR + LLM), optionally validates the data, and creates the expense in SuperFaktura. The source email is labeled for traceability. No migration required, easy to adapt per vendor.

The challenge

Teams using SuperFaktura often retype PDF data because native extraction (OCR/ICR) is missing. We needed a simple solution that handles varied invoice layouts while reducing errors and time. Each vendor has a different layout — GPT-4o Vision handled it better than expected. Slovak specifics like ICO, DIC, IC DPH, and variable symbol required explicit handling.

What went wrong along the way

First version ignored multi-page PDFs — some invoices have items on the second page. The vendor matching system created duplicate vendors because of different company name formats (s.r.o. vs spol. s r.o. vs without legal form). Solution: matching by ICO instead of name. Identifiers are more reliable than text names.

What we did