A toolkit built for payment engineers
FinDevKit is a browser-based toolkit for fintech developers. It covers the validation and debugging steps that come up repeatedly in payment workflows — IBAN checks, BIC parsing, SEPA file inspection, card validation, and more.
Developer-first
Designed for engineers working with payment APIs, SEPA workflows, and financial data. No accounts, no setup — just open and use.
Standards-accurate
Implements ISO 13616, ISO 9362, ISO 20022, and Luhn correctly — the same standards used by payment processors and banks.
Client-side only
All tools run entirely in your browser. Your IBANs, card numbers, and payment files are never transmitted to any server.
What it validates
IBAN validation using mod-97 checksum with country-specific length rules. Supports 70+ countries.
BIC/SWIFT parsing — extracts bank code, country, location, and branch identifier.
pain.001 structure validation: required fields, CtrlSum cross-check, duplicate EndToEndId detection.
Card number validation with IIN detection and structurally correct test card generation for sandboxes.