Payments software that keeps your data yours
PainXML exists because sending payment files to a third-party server shouldn't be the price of getting them right.
The problem
Banks reject malformed ISO 20022 files with cryptic errors. Teams waste hours fixing IBANs, BICs, and addresses by hand.
The insight
Everything a validator needs — an XSD engine, IBAN/BIC checks, a rulebook — can run in WebAssembly, entirely on-device.
The result
A fast, private validator and generator with no uploads, no logs, and no account required to get started.
Privacy is the feature
libxml2 compiles to WebAssembly so XSD validation happens in your browser tab. CSV/Excel parsing, IBAN and BIC checks, and XML generation are all client-side too. Your IBANs, BICs, and payment instructions never leave your device.
Try it yourself
Validate or generate a SEPA file in your browser — no sign-up needed.