Which countries use IBAN and what are the format differences?

Over 80 countries use IBAN including all EU countries, UK, Norway, Switzerland, and many Middle Eastern and North African countries. Each country has specific IBAN length requirements (ranging from 15 to 34 characters) and unique domestic account number formats within the IBAN structure.

What are the most common reasons for IBAN validation failures?

Common IBAN validation failures include: incorrect length for the specific country, invalid country code, wrong check digits due to transcription errors, invalid characters (non-alphanumeric), incorrect domestic account number format, or mathematical errors detected by the MOD-97 algorithm.

IBAN Validator - Validate International Bank Account Numbers

Q: How does IBAN validation work and what does it check?

IBAN validation involves multiple checks: verifying the country code against ISO standards, checking the correct length for that specific country, validating the format structure, and performing a MOD-97 checksum calculation to ensure mathematical correctness. This comprehensive validation ensures the IBAN is structurally and numerically valid.

About IBAN Validator

Validate International Bank Account Numbers (IBAN) with comprehensive country-specific checks and formatting validation. Our IBAN validator supports all 80+ countries that use the IBAN standard, ensuring accurate validation for banking, financial applications, and payment processing systems.

Supports all 80+ IBAN countries worldwide
Country-specific length and format validation
MOD-97 checksum verification
Real-time validation and error reporting
Banking industry compliance standards

How to Use IBAN Validator

Enter IBAN - Input the complete IBAN code (with or without spaces)
Automatic Detection - Country is detected from the first 2 letters
Validation - Length, format, and checksum are verified
Results - Get detailed validation results and error explanations
Integration - Use validation results in your applications

Frequently Asked Questions

What is an IBAN and why is it important?

IBAN (International Bank Account Number) is a standardized international format for bank account identification used in 80+ countries. It ensures accurate international money transfers by providing a unique identifier that includes country code, check digits, and domestic account details.

How does IBAN validation work?

IBAN validation involves checking the country code, verifying the correct length for that country, validating the format structure, and performing a MOD-97 checksum calculation on the rearranged IBAN to ensure mathematical correctness.

Which countries use IBAN?

Over 80 countries use IBAN including all EU countries, UK, Norway, Switzerland, many Middle Eastern and North African countries, and others. Each country has specific IBAN length and format requirements.

What makes an IBAN invalid?

Common reasons for invalid IBANs include: incorrect length for the country, invalid country code, wrong check digits, invalid characters, or incorrect domestic account number format for the specific country.

Can I validate IBANs programmatically?

Yes, you can integrate IBAN validation into applications using various APIs and libraries. Always validate IBANs both client-side and server-side for security and ensure compliance with banking regulations.

Understanding IBAN Structure

An IBAN consists of up to 34 alphanumeric characters with a specific structure that varies by country. Understanding this structure is crucial for proper validation and implementation.

IBAN Components:

Country Code (2 letters) - ISO 3166-1 alpha-2

Check Digits (2 digits) - MOD-97 validation

BBAN (up to 30 chars) - Basic Bank Account Number

Example: GB82 WEST 1234 5698 7654 32

Country Examples:

Country	Code	Length	Example Format
Germany	DE	22	DE89 3704 0044 0532 0130 00
France	FR	27	FR14 2004 1010 0505 0001 3M02 606
United Kingdom	GB	22	GB29 NWBK 6016 1331 9268 19
Spain	ES	24	ES91 2100 0418 4502 0005 1332
Italy	IT	27	IT60 X054 2811 1010 0000 0123 456

Common Use Cases

Banking and Finance:

International money transfers
Payment processing systems
Banking application integration
KYC and compliance verification
Account onboarding processes
Financial data validation
Cross-border payment validation
Banking API implementations

Development and Integration:

E-commerce payment forms
Financial software development
Accounting system integration
Mobile banking applications
Fintech platform development
Payment gateway validation
Database data cleanup
API data verification

IBAN Validation Algorithm

The IBAN validation process follows a standardized algorithm that ensures both structural and mathematical correctness of the account number.

Validation Steps:

Length Check: Verify the IBAN length matches the country's standard
Character Check: Ensure only valid alphanumeric characters are used
Country Code: Validate the first two letters against ISO 3166-1
Rearrangement: Move the first 4 characters to the end
Character Substitution: Replace letters with numbers (A=10, B=11, etc.)
MOD-97 Calculation: Calculate remainder when divided by 97
Result Verification: Valid IBAN should have remainder of 1

Implementation Example:

// IBAN Validation Algorithm

function

validateIBAN

(

iban

) {

// Remove spaces and convert to uppercase

const

cleanIban

=

iban

.

replace

(

/s/g

,

''

).

toUpperCase

();

// Check basic format

if

(!/^[A-Z]{2}[0-9]{2}[A-Z0-9]+$/

.test

(

cleanIban

)) {

return

false

;
}

// Rearrange: move first 4 chars to end

const

rearranged

=

cleanIban

.

slice

(

4

) +

cleanIban

.

slice

(

0

,

4

);

// Convert letters to numbers

const

numericString

=

rearranged

.

replace

(

/[A-Z]/g

,

char

=>
(

char

.

charCodeAt

(

0

) -

55

).

toString

()
);

// Calculate MOD-97

return

mod97

(

numericString

) ===

1

;
}