Where LLMs get payment matching wrong

Matching a payment to an invoice sounds like a perfect job for a language model. It mostly is. Here’s where it isn’t.

Bundled payments

One transfer, three invoices, a rounding difference. The model needs the open invoices for that customer, not just the payment text.

References that look right

Customers type invoice numbers from memory. We check every suggested match against amounts and dates before booking it.

Rules first

Exact matches go through rules, not the model. It’s cheaper, faster and easier to audit. The model handles what’s left.