Different tax codes in supplier business volume and settlement document

What causes this issue?

Settlement for a condition record of rebate arrangement &V1& is
performed using a billing document as the settlement document
(debit-side settlement). Processing is via the general billing interface
in the system.
In the process, the tax payable is determined via the appropriate
settings of the settlement material (tax classification material and
debtor, country of plant/company code (settlement at purchasing
organization level).
The resulting tax indicator determined - &V2& - differs from the tax
indicator &V3& of the supplier business volume. This is not allowed.

System Response

Settlement accounting with regard to condition record &V4& is not
possible.

How to fix this error?

Maintain a different settlement material or change the tax
classification of the settlement material. However, note that the
settlement material may also be subject to other usage in the system.
The (internal) number of the condition record affected is &V4&.

Error message extract from SAP system. Copyright SAP SE.