To show discount percentage on receipts there are two settings:
Navigate to Administrative > System Options > Receipt Options:
- Show Discount Percentage Threshold - if you want to show the percentage of each discount given you will put in 1%. This means any sale which is discounted over 1% will show the original price, discount percentage, and the price they are paying.
This can be configured for any minimum discount amount. For example, if you only want to show the discount percentage if it's over 25%, you can enter 25 here.
If you do not want a discount percentage to show, but instead want retail / your price, you would set the discount percentage threshold setting at 100.
- Show Discounts on Each Line - set this option to True.