An IBAN (International Bank Account Number) is a European account number which replaces your previous Belgian 12-digit account number.
A European account number has no more than 34 characters and has a fixed length per country.
In Belgium, each IBAN is 16 characters long:
You can find the IBAN for your BNP Paribas Fortis account on your account statements. You can also easily calculate it yourself here.
My Belgian account number:
Do you have a beneficiary's IBAN for a transfer? Please verify that the IBAN is correct.