BankCheck is a free, open tool for validating bank account numbers. Paste an IBAN, a US routing number, or a UK sort code and get instant validation with a detailed breakdown of every segment.
The tool auto-detects the format you enter, validates it using the correct algorithm, and explains exactly what each part of the number means. If something is wrong, it tells you why and how to fix it.
Your data never leaves the browser. All validation runs entirely client-side using JavaScript. No bank numbers are sent to any server, logged, or stored. There are no analytics trackers, no cookies, and no third-party scripts.
This is a deliberate architectural choice. Bank account numbers are sensitive financial data, and we believe validation tools should not require you to trust a server with that information.
Read our full Privacy Policy.
Validated using the MOD-97 algorithm defined in ISO 13616. Supports 40+ countries with country-specific length and structure checks.
Verified using the ABA 3-7-1 weighted checksum algorithm, with Federal Reserve district identification based on the FedACH directory.
Format-validated and matched against bank data to identify the institution and branch. Based on the industry sort code directory.
Disclaimer: BankCheck is a validation tool that checks the mathematical and structural correctness of bank numbers. A valid checksum does not guarantee that an account exists or is active. Always confirm account details with your bank before making transfers.