IBAN Checker

This tool validates IBAN strings against ISO 13616 rules, verifying the country code, length, and checksum for international bank accounts. It is designed for finance teams, payments operations, accounting auditors, and developers integrating validation into APIs or batch processing pipelines. It is used when processing international transfers, supplier onboarding, or payment file reconciliations to catch formatting and checksum errors before transmission.
Conceptually, the system normalizes input by removing spaces and converting to uppercase, checks for allowed characters, then applies country-specific length checks and the standard checksum algorithm (move the first four characters to the end and compute modulo 97 after mapping letters to numbers). If any step fails, the result is invalid with a precise reason.
Outputs include is_valid, country_code, check_digits, and normalized_iban, plus optional details such as length and BBAN components if derivable. The tool is designed to be deterministic and machine-parseable to feed into data quality checks in ERP, CRM, or payment gateways.
Use cases include onboarding suppliers, cross-border payroll, vendor payments, and batch file processing, where early validation prevents failed transfers and reduces operational risk.