Add a voucher discount to your voucher
Go to the Voucher Service
Select List Vouchers.
Click edit on the desired voucher.
Enter the discount value to the Advanced tab of the voucher editor.
Discount formats can be specified as a fixed monetary amount or a percentage, both with optionally up to 2 decimal places.
Click Save Changes.
Note: 10 will give a 10 EUR/USD/GBP fixed amount discount off the value of the voucher.
5.50% will give a 5.5% discount off the value of the voucher.
Appearance on the voucher booking engine