An invoice can add up perfectly and still belong to the wrong supplier.

At Procys, my document-processing work combines OCR and LLM layout reasoning with deterministic validation and checks against existing records.

When I evaluate this kind of pipeline, I'd include two suppliers with similar names. The test invoice should carry an identifier that matches only one of them. I'd check whether the system preserves that identifier, links the right counterparty and flags conflicting evidence for review.

I treat field extraction and counterparty matching as separate acceptance checks.

For a client planning invoice automation, I'd agree those matching rules before connecting extracted data to the next system.