Purchasing inventory items and dealing with the sales tax So several stores (California) I source from don't accept seller's permit for sales tax, so I'm paying the sales tax to purchase the items. When I add the price of the items to my inventory spreadsheet, do I factor in the sales tax? If I purchase multiple items, do I just average the total cost?

Example: Shirt is $5.00 so the total is $6.00 with tax to purchase.