Account numbers may vary from country to country and sometimes even from bank to bank.
That is why the European Committee for Banking Standards (ECBS) has come up with an international standard for account numbers: the International Bank Account Number (IBAN). Now, all International Payment Instructions (IPIs) must specify both the IBAN and the Bank Identifier Code (BIC) for cross-border payments in Europe. Please ask your bank for your IBAN and BIC.