Hi, 

Is there a way to link a sales part (inventory or non-inventory) to an income type for tax withholding puposes? 

Scenario: The customer is setup with withholding tax, but only some services/parts are subject to withholding taxes. I would like to default the withholdong taxes using two criteria: 1- the customer setup and 2- sales part setup. However, it seems I can only define the withholding tax at the customer level. 

Note: 

I tried tax classes but tax withholding are not available here.

Thanks