IBAN Validator: Check Any International Bank Account Number

How to use this tool

1. Choose a task. Open Validate to check an IBAN, or Generate to calculate check digits from a country and domestic BBAN.
2. Review the result. Check the country, expected length, character format, and MOD-97 result. For mapped countries, review the labeled BBAN fields.
3. Copy or verify details. Copy an electronic IBAN without spaces or a print version grouped in fours. Confirm generated or validated banking details with the bank before paying.

IBAN and BBAN structure

An International Bank Account Number (IBAN) begins with a two-letter country code and two check digits. The rest is the Basic Bank Account Number (BBAN), a country-specific identifier for a domestic account. For example, in GB29 NWBK 6016 1331 9268 19, GB is the country, 29 is the IBAN check digit pair, and the remaining characters are the BBAN.

The validator removes spaces and accepts lowercase input. It checks the country code against its built-in length list, then checks the expected length, allowed characters, and MOD-97 checksum. For Germany, the United Kingdom, France, the Netherlands, Belgium, Spain, Italy, Switzerland, and Poland, the result also labels the BBAN fields represented in the local layout map. Other countries remain visible as a complete BBAN so the tool does not invent bank, branch, or account boundaries it has not mapped.

Country IBAN lengths and SEPA scope

The table contains all 86 country codes in this tool's local length registry. Search by a country name or code to find the required total IBAN length. The SEPA column describes whether a country or territory is within the European Payments Council's published scheme geographical scope; it does not confirm that a particular bank or account participates in a scheme. Length and SEPA data are static browser-side references and may lag later registry changes.

The country formats are registered under ISO 13616 and published by Swift's IBAN Registry. See the European Payments Council's SEPA country list for the current geographical scope and scheme details.

IBAN vs. SWIFT/BIC

An IBAN identifies an account within a country's numbering format. A SWIFT/BIC identifies a financial institution and may include a branch suffix. A payment may request one or both, but the fields are not interchangeable. Use the SWIFT/BIC Code Validator to check a BIC's format; it also does not identify the account holder or prove that a bank accepts a payment.

How IBAN check digits work

To validate an IBAN, the first four characters move to the end, letters convert to numbers (A=10 through Z=35), and the resulting digit string is evaluated modulo 97. A remainder of 1 passes the checksum. The advanced result shows that remainder so users can see why a changed digit can make an otherwise correctly sized IBAN fail.

The Generate tab applies the same rule in reverse. It places 00 after the BBAN and country code, calculates the remainder, then sets the check digits to 98 − remainder using two digits. For example, the supplied German BBAN 370400440532013000 produces check digits 89. The tool calculates locally and does not query a bank, account directory, or payment API. A calculated checksum is a format check, not proof of account existence or ownership. For the nine countries with mapped BBAN layouts, it also checks field character types; for other country codes, generation checks BBAN length and alphanumeric characters only.

Privacy and practical limits

IBAN and BBAN values are processed in this browser and are not sent to a validation service. The tool does not perform bank-name or BIC lookup, domestic account checksum verification, account ownership checks, or payment authorization. When preparing a transfer, use details supplied by the intended recipient and confirm them through a trusted channel.