We sell house gift certificates that are redeemed with custom tender payment option. First of all, there is no option to add tip when paying with custom tender option. Secondly, when a service charge is applied (to go around the no tip option), the service charge shows up as unpaid balance on the reports, even though full payment is redeemed with the custom tender. For example, food bill is $50 + $10 service charge. You choose custom tender ("redeem house gift certificate") for the amount ($60). Payment shows up as $60, but under "unpaid balance" it shows $10.