Do you know about any solution for the tax on the A/P side?

Are you referring to Use Tax?

@Rich Keller Yes Use tax on the purchasing side

There are varying levels: 1. You can build a transaction saved search based upon a flag on both the Vendor and the item that are "Use Tax Eligible" (you carry those fields over to the header and line levels of the transactions for the search) 2. You can develop scripting which can more consider the items and address on transactions to automate the process and reporting into a tax entity