We use QB POS and decided yesterday to Add a tax code of 3% and named it "card fee"

So when a customer checks out if they are using a card. We toggle the tax to "card fee" 

The "tax" was setup as a multiple rate.

 6.5%state

.5% county

2.125% City

3% card fee.

It is way faster than manually adding an item and correct as far as math and coding the money.  

Can look daily/weekly/monthly/annually and see how much was collected.  The way I see it. It is more than getting $0 from the customers and easier for the clerks to do.