How to Determine Place of Supply not ship to or bill to

R12.1.3 Payables and Purchasing

We need to set up a rule that will determine place of supply that is different than the Bill to or Ship to.

Example - An audit is being done in several provinces.

The Bill to address is ALWAYS an address in   Province A

The Delivery (Ship To) of the service is in each of the regional offices, Provinces A,B, C,D, E

The PO was issued in Province C

Our rule must state that if the purchase is for Classification code X the Tax is to be determined based on the PO Issuing Office.