You can designate tax to be included at the item level but I'm not aware of any way to do this at the payment type level. You could create a duplicate of each product you offer that has TAX turned off but that sounds like a cumbersome and terrible option to maintain.
The easiest workaround I can think of is to remove tax from the ticket before swiping the ccard. While an extra step is required it would achieve the results you are going for.
On the iPad POS you do this by removing tax as you add the item to ticket or:
- "Current Sale" (top of screen)
- "Tax"
- Select the red dot with dash and "Delete" the Tax
- Select "Done" - your ticket now exludes Tax and is ready to accept payment.
On the iPad POS you do this by following steps 1-5 above.
As school starts up here in Oklahoma, we have a tax-free weekend on many supplies. The method above is what we use and is the easiest I've found at the moment .
Take care of yourself and, as life provides, someone else too.
