IBAN Validator and Parser

What is an IBAN Validator and Parser?

An IBAN Validator and Parser is a tool that checks the structural and mathematical validity of an International Bank Account Number (IBAN) and extracts key details such as the country code, Basic Bank Account Number (BBAN), and formatted representation. The IBAN is an internationally standardized system of identifying bank accounts across national borders, used primarily in Europe, the Middle East, and parts of the Caribbean and Africa.

This IBAN validator performs real-time validation using the ISO 13616 standard and the IBAN Registry maintained by SWIFT. It verifies the length, format, and checksum of the IBAN, and also checks whether the IBAN is a QR-IBAN (used in Switzerland and Liechtenstein). The parser extracts the country code and BBAN for further analysis.

How Does IBAN Validation Work?

IBAN validation follows a two-step process. First, the tool checks that the IBAN has the correct length and structure for the specified country. Each country has a predefined IBAN length (e.g., Germany uses 22 characters, France uses 27). Second, it performs the modulo 97 checksum validation, which is the mathematical core of IBAN verification.

The modulo 97 algorithm works by moving the first four characters (country code and check digits) to the end of the string, converting all letters to numbers (A=10, B=11, ..., Z=35), and then checking whether the resulting number is divisible by 97 with a remainder of 1. This ensures that the IBAN has not been altered due to common data entry errors such as transposed digits or incorrect characters.

Countries and IBAN Lengths

The IBAN standard covers over 70 countries, each with a specific length and format. Here are some common examples:

• Germany (DE): 22 characters - e.g., DE89 3704 0044 0532 0130 00
• France (FR): 27 characters - e.g., FR76 3000 6000 0112 3456 7890 189
• United Kingdom (GB): 22 characters - e.g., GB29 NWBK 6016 1331 9268 19
• Italy (IT): 27 characters - e.g., IT60 X054 2811 1010 0000 1234 567
• Spain (ES): 24 characters - e.g., ES79 2100 0418 4512 3456 7891
• Netherlands (NL): 18 characters - e.g., NL91 ABNA 0417 1643 00
• Switzerland (CH): 21 characters - e.g., CH93 0076 2011 6238 5295 7
• Belgium (BE): 16 characters - e.g., BE68 5390 0754 7034

What is BBAN?

The Basic Bank Account Number (BBAN) is the country-specific portion of an IBAN that follows the first four characters (country code and check digits). It identifies the specific bank and account number within the country's banking system. The BBAN structure varies by country but typically includes a bank identifier, branch code, and account number. The IBAN parser extracts this component for further processing or record-keeping.

What is a QR-IBAN?

A QR-IBAN is a special type of IBAN used in Switzerland and Liechtenstein for the QR-bill payment system. QR-IBANs are identifiable by a specific range of account numbers and are used exclusively for receiving QR-bill payments. The IBAN validator checks whether the provided IBAN falls within the QR-IBAN range, which is indicated by account numbers between 30000-00001 and 31999-99999 for Swiss IBANs (CH).

Common IBAN Errors

When validating IBANs, the tool can detect several types of errors:

• No IBAN Provided: Empty or blank input
• No IBAN Country: The country code does not match any known IBAN country
• Wrong BBAN Length: The BBAN portion is too short or too long for the specified country
• Wrong BBAN Format: The BBAN contains invalid characters or structure
• Checksum Not Number: The check digits are not numeric
• Wrong IBAN Checksum: The modulo 97 checksum validation failed
• Wrong Account Bank Branch Checksum: Country-specific internal checksum failed
• QR-IBAN Not Allowed: The IBAN is a QR-IBAN but QR-IBANs are not permitted for this use case