Common question we get on Sharp Cash Registers and SAM4s Cash Registers is how to make the total sales taxable after the discount. So as an example the business owner wants the cash register to charge sales tax after a discount like this $10.00 sale with a 10% discount and you want to tax $9.00 not $10.00
So you program the discount key to be taxable YES TAXABLE that was it reverses the tax that would have been charged. So if you have a 10% tax the sales tax on $10.00 would be $1.00 but you apply a discount of 10% that is taxable the discount will be $1.10 so your gross sale will be $9.90
Hope that helps! Works the same rather discount is based on percentage or dollar amount.