🏦 IBAN Validator - Format & Mod-97 Check
Professional IBAN validator that performs comprehensive format validation, mod-97 algorithm verification, country-specific length checks, and BBAN component parsing. Essential for banking applications, payment processing, and financial system debugging.
IBAN Validation Results:
DE89 3704 0044 0532 0130 00
Germany • Length: 22 chars • Mod-97 checksum: Valid
🔍 IBAN Component Analysis
📊 Validation Summary
Country & Structure
22 chars (DE)
Checksum Valid
Structure Valid
🧮 Mod-97 Algorithm Calculation
🌍 Country Information
Germany
22 characters
8n,10n
How to Use This IBAN Validator - Format & Mod-97 Check
How to Use the IBAN Validator
- Enter IBAN: Paste one or more IBANs in the input field (spaces are automatically removed)
- Choose Detail Level: Select basic validation or detailed breakdown with technical information
- Enable Options: Check boxes to show component breakdown and mod-97 calculation steps
- Validate: Click to process and see comprehensive validation results with country information
Pro Tips:
- Use "Technical" mode to debug failed IBANs and see mod-97 calculation steps
- Enable "Component Breakdown" to identify bank codes and account numbers
- Validate multiple IBANs at once by entering one per line
- Copy validation results for documentation and audit trails
How It Works
How IBAN Validation Works
IBAN validation follows the ISO 13616 standard with multiple validation layers:
Format Validation: Checks country code (2 letters), check digits (2 numbers), and total length against country-specific requirements.
Mod-97 Algorithm: The mathematical checksum that prevents 99% of input errors. The algorithm moves the first 4 characters to the end, replaces letters with numbers (A=10, B=11, etc.), and calculates remainder when divided by 97. Valid IBANs produce remainder 1.
BBAN Structure: Validates the Basic Bank Account Number format according to each country's banking system requirements.
Country Database: Cross-references against 75+ countries with specific length requirements, BBAN formats, and validation rules.
The tool provides detailed breakdowns showing country identification, bank codes, account numbers, and step-by-step mod-97 calculations for technical verification and debugging.
When You Might Need This
- • Validate international bank transfers before sending payments to prevent costly errors
- • Debug failed payment processing due to IBAN format errors in banking applications
- • Verify IBAN format compliance for regulatory reporting and audit requirements
- • Check IBAN country codes and length requirements for multi-country payment systems
- • Validate mod-97 checksum calculations for financial system integration testing
- • Process bulk IBAN validation for payment batch processing and verification
- • Verify IBAN structure for accounting software integration and data imports
- • Debug IBAN parsing issues in financial data processing and payment gateways
- • Validate IBAN format for customer onboarding and account verification processes
- • Check IBAN authenticity for fraud prevention and payment security systems
Frequently Asked Questions
What is the IBAN mod-97 algorithm and how does it work?
The mod-97 algorithm is the mathematical checksum used to validate IBANs. It involves moving the first 4 characters to the end, replacing letters with numbers (A=10, B=11, etc.), then dividing by 97. A valid IBAN produces a remainder of 1. This prevents 99% of transcription errors.
Why do some valid-looking IBANs fail validation?
IBANs can fail validation for several reasons: incorrect country code, wrong length for the country, invalid characters, failed mod-97 checksum, or incorrect BBAN structure. Even if an IBAN looks correct, it must pass all format checks and the mathematical mod-97 calculation to be valid.
What's the difference between IBAN country codes and length requirements?
Each country has specific IBAN requirements: a 2-letter country code (like DE for Germany), fixed length (Germany is 22 characters), and BBAN structure. For example, German IBANs are 22 chars with format DE + 2 check digits + 8-digit bank code + 10-digit account number.
How can I identify the BBAN (Basic Bank Account Number) from an IBAN?
The BBAN is everything after the country code and check digits. For IBAN 'DE89 3704 0044 0532 0130 00', the BBAN is '370400440532013000'. The BBAN structure varies by country - German BBANs have 8-digit bank codes followed by 10-digit account numbers.
What should I do if an IBAN passes format validation but payment fails?
Format validation only checks structure and checksum, not if the account exists. Payment failures despite valid format usually mean: closed account, frozen account, currency restrictions, or bank processing issues. Contact the recipient's bank or use additional account verification services.