IBANs look like a random jumble of letters and numbers, but they’re actually a tightly specified format with a built-in checksum. This tool decodes that structure and tells you, character by character, whether an IBAN is well-formed.
What Is the IBAN Validator?
The IBAN Validator checks an International Bank Account Number against the ISO 13616 mod-97 checksum, verifies its length against the expected length for its country, and shows a breakdown of the country code, check digits, and BBAN (Basic Bank Account Number).
How to Use It
- Open the tool at /tools/iban-validator.
- Type or paste an IBAN — spaces are ignored automatically.
- The badge updates instantly with a valid/invalid verdict and the specific reason if it fails.
- Try one of the example buttons (Germany, UK, France, Spain) to see correctly formatted IBANs.
Key Features
- ISO 13616 mod-97 checksum, computed digit-by-digit to avoid floating-point precision issues on long numbers.
- Per-country length validation against a lookup table covering roughly 70 IBAN-participating countries.
- Full breakdown of country code, check digits, and BBAN.
- Runs entirely in your browser — no IBAN you type is ever sent anywhere.
When to Use This Tool
- Validating IBAN input in a form before submitting it to a payment processor.
- Debugging why a particular IBAN is being rejected elsewhere.
- Learning the IBAN structure for a specific country.
Try It Now
Open IBAN Validator directly, or press ⌘K and type the tool name from anywhere on the site.
Part of the Security & Validators collection on WebdevToolbox — free, browser-based developer tools with no login required.