WHT Override at Payment Level

Summary

WHT Override at Payment Level

Content

Business wants to override WHT Tax at payment level for few cases but I don't find this field neither in Payment UI nor in Payment process request. 

As per country rules, all WHT tax should be generated at Payment level so we can't modify the WHT tax amount at Payment level. If I try to update the WHT tax amount at Invoice level and its generating at Invoice level itself even though WHT Tax code defined as at "Payment".

Even though calculation point at payment level, if override its automatically applying at invoice level itself