IBAN Validator

Validate IBAN (International Bank Account Numbers).

Input

Output

Examples

Example 1

GB82 WEST 1234 5698 7654 32

Example 2

DE89 3704 0044 0532 0130 00

Example 3

FR14 2004 1010 0505 0001 3M02 606

Understanding IBAN Structure and Validation

IBAN (International Bank Account Number) is a standardized format for identifying bank accounts across borders. It consists of a country code (2 letters), check digits (2 numbers), and a Basic Bank Account Number (BBAN) up to 30 alphanumeric characters—totaling 15-34 characters depending on country.

The validation uses the mod-97 algorithm defined in ISO 13616. The IBAN is rearranged by moving the first four characters to the end, converting letters to numbers (A=10, B=11...Z=35), then calculating modulo 97. A valid IBAN produces a remainder of 1.

Each country has specific IBAN length requirements: Germany (DE) uses 22 characters, UK (GB) uses 22, France (FR) uses 27, while Cyprus (CY) uses 28. Validation must check both the mod-97 checksum and country-specific length rules.

Why IBAN Validation is Essential

IBAN validation prevents costly international payment failures. Incorrect IBANs cause transfers to be rejected, often with fees charged by intermediary banks. Validating before submission saves money and avoids payment delays that can damage business relationships.

SEPA (Single Euro Payments Area) transactions require valid IBANs. Submitting invalid numbers results in payment rejection and potential penalties from banks. Pre-validation ensures compliance with EU banking regulations and smooth cross-border transactions.

User experience improves dramatically with real-time IBAN validation. Customers immediately see formatting errors or invalid check digits, preventing submission mistakes. Auto-formatting with spaces every 4 characters makes long numbers easier to read and verify.

IBAN Validation Implementation Best Practices

Always remove spaces and convert to uppercase before validation—IBANs are case-insensitive and commonly written with spacing for readability. Normalize input before applying the mod-97 algorithm to avoid false negatives.

Validate country code separately: Check if the two-letter code is a recognized IBAN country. Not all countries use IBAN (USA, Canada, Australia don't), so clearly communicate this to users entering non-IBAN accounts.

Don't confuse validation with existence: The mod-97 check only verifies mathematical correctness, not whether the account actually exists at a bank. For real account verification, use bank verification APIs or micro-deposit confirmation.

Consider additional validation layers: Check IBAN registry for country-specific rules, verify bank code format against national standards, and optionally use BIC/SWIFT code lookup to cross-reference bank information with the IBAN.

IBAN in Global Payment Systems

IBAN is mandatory for SEPA transfers across 36 European countries and used in 80+ countries worldwide. When collecting payment information for international customers, always support IBAN format alongside domestic account number formats.

Display IBAN with proper formatting: Group characters in blocks of 4 for readability (DE89 3704 0044 0532 0130 00). This matches bank statements and reduces transcription errors when users enter numbers manually.

Store IBANs securely: While not as sensitive as credit cards, IBANs can enable direct debits. Follow data protection regulations like GDPR when storing and processing account numbers. Encrypt at rest and in transit.

Provide clear error messages: Instead of generic 'Invalid IBAN', specify what's wrong—'Invalid country code', 'Check digits don't match', 'Wrong length for DE (Germany)'. Specific feedback helps users correct mistakes faster.

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IBAN Validator - International Bank Account Number Checker

Validate IBAN (International Bank Account Numbers).

Validate International Bank Account Numbers (IBAN) using the official mod-97 algorithm. Perfect for international banking, payment processing, financial applications, and form validation. Checks format, country code, check digits, and overall validity according to ISO 13616 standards.

Keywords

#iban validator#bank account validator#iban checker#international banking#sepa validator

Looking for more? Explore other Validators tools

IBAN Validator

Validate IBAN (International Bank Account Numbers).

Input

Output

Examples

Example 1

GB82 WEST 1234 5698 7654 32

Example 2

DE89 3704 0044 0532 0130 00

Example 3

FR14 2004 1010 0505 0001 3M02 606