"Include Tax" on calculation


I am struggling to understand the purpose behind “Include Tax” when setting up a Calculation Type. I have read a couple of different posts on this topic, but I’m either missing something, or they didn’t quite get to the issue I am experiencing…

My tax rate is 16%

My items are sold as “including tax” so a $100 item is really $86.21 + $13.79 tax

If a customer wants to pay by credit/debit card, then I charge an extra 5% (again, this fee should include tax, then same way as my pricelist prices do). So really, the $5 card fee is $4.31 + $0.69

But at the moment, these charges, along with rounding, are listed in my receipt as being excluded from tax.
For example:

<J>Net taxable|[=F(TN('{TAXABLE AMOUNT}'))]
<J>16% IVA|[=F(TN('{TAX AMOUNT}'))]
<J>Ticket Total|[=F(TN('{TICKET TOTAL}'))]


Tax exempt      5.00
Net taxable    86.21
16% IVA        13.79
Ticket Total  105.00

But I would like this to be…

Tax exempt      0.00
Net taxable    90.52
16% IVA        14.48
Ticket Total  105.00

I have two types of Calculation defined…

A Credit Card surcharge
Applied by pressing a button on the payment screen

A Rounding (up and down)
Automatically applied when pressing a cash button on the payment screen

I have enabled “Include Tax” on both of these.

What else should I be doing.

This whole thing really confuses me, because I don’t see how or where I would define which type of Tax Template should be used by the calculation…

Any help would be greatly appreciated!


SWAG, the “Include Tax” flag is probably to tell the Calc to do it’s math on the Plain total (without tax) or on the complete total (with tax).

Because as you mention, if the flag was intended to use a particular Tax Rate, then the Calc would require a parameter for the Tax Template to use in the Calc.

It sounds like in your case then, you probably will not be able to accomplish your end result by using a Calculation Type/Selector.

You could possibly use an AMC button and some Ticket Tags to achieve your result in a roundabout way.