TAXUSJ with material master tax ind., State specific tax code determination

Hello,

We need to determine tax code in PO using tax procedure TAXUSJ .There are different plants in different states of the US and face a problem of correct derivation of the tax code on purchase orders in SAP.

Apparently, a material can be liable to tax in 1 state, and not liable for tax in another state. Tax indicator is country specific and not state specific (or plant specific). Hence we can have only one tax-indicator in material master. We setup conditions in MEK1 transaction, but did not solve the purpose.

How is this set up in standard SAP? How to determine tax-code in TAXUSJ?

Thanks.