Validate an IBAN online instantly using this free, browser-based checker that verifies the format and checksum of any international bank account number. Paste the IBAN into the field and get an immediate result confirming whether it is structurally valid. No signup is required, and the number is never transmitted to any external server.
The IBAN Validator is a tool for verifying the format and mathematical validity of International Bank Account Numbers (IBANs) used in international wire transfers and SEPA transactions. An IBAN encodes a country code, check digits, and the bank account number in a standardized format that enables automated routing of international payments. This tool accepts an IBAN string, checks its length against the expected length for the identified country, and verifies the check digit using the MOD-97 algorithm specified by the ISO 13616 standard. A valid IBAN does not guarantee the account exists, but it does confirm that the format is correct and the number has not been mistyped. This is useful for businesses processing supplier payments, developers integrating payment forms, finance teams verifying account details before initiating transfers, and individuals double-checking bank account details received from counterparties.
The IBAN system was developed by the International Organization for Standardization (ISO) and the European Committee for Banking Standards (ECBS) to facilitate automated processing of cross-border payments, particularly within the SEPA (Single Euro Payments Area) zone. Prior to IBAN adoption, international transfers required separate routing codes, account numbers, and bank identifiers that varied by country, leading to frequent errors and manual intervention by bank staff. IBAN reduces these errors by embedding country-specific format validation and a check digit directly in the account number. The MOD-97 check digit algorithm works by rearranging the IBAN (moving the first 4 characters to the end, replacing letters with numbers where A=10, B=11, etc.) and verifying that the resulting large integer is divisible by 97. This catches approximately 98.9% of single-character errors and virtually all transposition errors (swapping adjacent digits), which are the most common human data entry mistakes. IBAN lengths vary by country: German IBANs (DE) are 22 characters, UK IBANs (GB) are 22 characters, French IBANs (FR) are 27 characters, and Saudi Arabian IBANs (SA) are 24 characters. The validator checks the length against the correct country specification in addition to the check digit, providing a more thorough validation than check digit alone. For developers building payment forms, integrating IBAN validation with real-time feedback prevents invalid submissions before they reach the payment processing API.