IBAN Generator - Generate Fictional Dutch IBAN Numbers with Modulo 97

A Dutch IBAN (International Bank Account Number) consists of exactly 18 characters and follows a fixed format: the country code NL, followed by 2 check digits, a 4-letter bank code and a 10-digit account number. The full format is: NLcc BBBB 0000 0000 00.

The mod-97 algorithm

The check digits in an IBAN are calculated using the mod-97 algorithm (ISO 7064). This works in the following steps:

1. Move the first 4 characters (country code + check digits) to the end of the IBAN.
2. Replace each letter with a number: A=10, B=11, ..., Z=35. The country code NL becomes 23 and 21.
3. The resulting number is divided by 97. The remainder (modulo) must equal 1.
4. When generating, the check digits are chosen so that 98 minus the modulo-97 remainder yields exactly the correct value.

Supported bank codes

This IBAN generator supports the main Dutch bank codes:

• ABNA — ABN AMRO Bank
• INGB — ING Bank
• RABO — Rabobank
• SNSB — SNS Bank
• ASNB — ASN Bank
• KNAB — Knab
• TRIO — Triodos Bank
• BUNQ — bunq

Example: For IBAN NL91 ABNA 0417 1643 00, the check digits 91 are calculated via the mod-97 algorithm. The full number (after rearrangement and letter replacement) divided by 97 yields remainder 1, confirming the IBAN is valid.

All IBAN numbers generated by this tool are fictional and not linked to real bank accounts. Use them for testing form validation, API integrations or complete test datasets. Combine them with a fictional BSN number for realistic test data.