AI Invoice Checker

Outgoing B2B invoices get sent with broken IBANs, VAT math errors, or missing reverse-charge notes. One bad invoice triggers a payment dispute, a chargeback, or — worst case — a fraudulent IBAN swap the recipient doesn’t catch.

I shipped the original internal tool after we caught an invoice where the stated VAT was €842 off from what net × rate actually equaled. Nobody had caught it in three rounds of manual review. That’s what deterministic arithmetic checks are for — humans can’t see rounding.

• ▸An LLM will cheerfully “confirm” a bogus IBAN
• ▸VAT arithmetic needs exact decimal math, not probabilistic text
• ▸Format regexes for 27 EU VAT ID shapes don't need a language model