Why does the Data API not return an IBAN or Account Number and Sort Code for some Wise accounts?

Wise users can open currency accounts without any attached bank details. This means that the account does not have any actual IBAN or bank account number and sort code. As such no account numbers are returned via the Data API for these accounts.

Users can contact Wise to request unique bank details for their account in the Wise app, and once they do, it reflects on the API, and an IBAN should be returned.

You can find out more about this on the Wise website here.