IBAN Validator & Formatter

Validate IBANs with the ISO 13616 mod-97 algorithm. Format, decode, and look up country lengths.

Last reviewed: April 2026
Reviewed by , software engineer · last updated April 2026

New to this tool? Click here for instructions

Enter an IBAN and click Validate / Format.

How to Use the IBAN Validator

To use the IBAN Validator, follow these steps:

1. Validate Mode: Paste any IBAN (with or without spaces) into the input field and click 'Validate / Format'. The tool will check the mod-97 checksum and report the country, check digits, BBAN, and bank code.

2. Format Mode: Use the same input as above. The tool will also display the IBAN in a paper/print format with spaces every 4 characters (e.g., GB82 WEST 1234 5698 7654 32).

When to Use the Tool in Real Workflows

Use the IBAN Validator in real workflows when you need to ensure the accuracy of IBANs for international transactions. This includes when sending money to another country, verifying IBANs provided by clients or partners, and ensuring compliance with SEPA regulations.

How It Works

The IBAN Validator works by applying the ISO 13616 mod-97 checksum algorithm to validate IBANs. It checks the country code, check digits, and BBAN to ensure they are correct. The tool also formats IBANs for better readability, making it easier to identify and use them in various banking and financial applications.

Tips, Edge Cases, or Limitations

1. Country-Specific Formats: The tool supports various country-specific formats for BBANs. Ensure you input the IBAN in the correct format for your country.

2. Client-Side Processing: The validation and formatting are done entirely on the client side using JavaScript, ensuring your data remains secure and private.

3. SEPA Compliance: The tool is particularly useful for businesses operating within the Single Euro Payments Area (SEPA), where IBANs are mandatory for all credit transfers and direct debits.

Frequently Asked Questions

The International Bank Account Number (IBAN) is a globally standardized format for identifying bank accounts, defined by ISO 13616 and maintained by SWIFT.
IBAN validation uses a modular arithmetic check defined in ISO 7064. The tool removes spaces, converts letters to uppercase, rearranges the string, and computes the number modulo 97 to validate the IBAN.
The Basic Bank Account Number (BBAN) is the variable-length part of an IBAN that is specific to the country where the account is held.
Over 80 countries have adopted IBANs voluntarily, including Jordan, Saudi Arabia, Brazil, and most of the Caribbean. The United States, Canada, Australia, China, Japan, and India do not use IBANs for domestic transfers.
IBAN is a global standard for identifying bank accounts, while SWIFT/BIC is used for identifying banks and financial institutions. IBAN is used for both domestic and international transactions, while SWIFT/BIC is used for international payments.