Hello,

Reverse VAT was not designed to be used with VAT Zones function.
VAT Zone overrides VAT percentage and calculation method set in VAT Codes setting and Tax Rules setting.
In order to get a correct VAT result in your case, please use VAT Zone = Domestic.
If your customers have a need to use VAT Zones together with Tax Rules, please send us a wish describing the need.

Kind Regards
HansaWorld Team