where to set Service Performed Country in order to create a VAT voucher

 Hi guys,

We need to create a voucher with VAT, but we I clicked the ''VAT Summary'', I got the following message

Service Performed Country is required.  (9060,312) 

You must supply this field in order for VAT default values to be obtained.

I thought there was something with the Business Unit I used because all was OK when I changed another BU.

However, I can't find where to set the Service Performed Country. could you please tell me the pathway of this?

Many thanks in advance!

Kila