Only the bank servicing an account can provide the correct International Bank Account Number (IBAN) of that account and the related Bank Identifier Code (BIC).
If you need an IBAN, you need to contact the owner of the account. If you attempt to generate IBANs of your suppliers or other business partners, you risk having incorrect IBANs.
If you use an incorrect IBAN in your cross-border payment instructions, you risk making payment to the wrong account or incurring a delay in payment and higher processing fees.
Who must do what
Each Bank in the European Union servicing euro accounts must:
Calculate the IBANs of the accounts they service
Inform their customers of the IBAN of the account and the BIC code of the bank on their statements or in an annex to the statement
Each Account Owner must:
Inform their business partners of their IBAN and BIC on their letterhead and other documents used in cross-border invoicing in the EU
Each Ordering Customer must:
Use the correct IBAN and BIC in their euro cross-border credit transfer, particularly within the EU and for transfers up to 12500€, if they wish to benefit from the fees applied to domestic transfers
Why
Tools that automatically generate IBANs from domestic account numbers are not guaranteed to give correct IBANs because:
The IBAN is based on the Basic Bank Account Number (BBAN)
The BBAN cannot always be automatically derived from the domestic account number
Nor can the BIC always be derived from the BBAN
To convert your basic bank account number to an IBAN, you can use a tool IBAN Calculator
USD 1.0412