SEPA mandate &1 cannot be used with bank details &2

What causes this issue?

You are trying to use SEPA mandate &v1& in conjunction with bank details
&v2&. The IBAN of bank details &v2& is &v3&. The IBAN of the SEPA
mandate &v1&, however, is &v4&.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

You cannot use SEPA mandate &v1& in conjunction with bank details &v2&.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.