In that case, we invite you to remove the account information that you have collected to date for this customer, via the following endpoint: https://documentation.ibanity.com/api#delete-customer.
It is also possible to remove the customer data for a specific account via this endpoint: https://documentation.ibanity.com/api#delete-account.
Ibanity will cascade these instructions to the concerned financial institutions, in order for them to update their authorization dashboards if they have one.