MICROS RES 3700 - Changing Service Charge calculation

[microsap]

Hi
I need some help with an old RES ver 5.x system that seems to be working fine.
Is there any way to change how service charges are calculated. We've looked at all the options but cannot find a way to apply the service charge calculation to both the total and the taxes
Could this be done as a SIM?
thx

 

[Albert Carrillo]

If you have add-on taxes, service charge will be calculated from the amount without taxes.
If you want it to be calculated with the amount with taxes, you can multiply your Service Charge rate by the tax ratio.

Service Charge (15%): 15%

Item 10$
Add-on Tax (10%) 1$
Service Charge (15%) 1.5$ <----- 15% of 10$
Total: 12.5$

Service Charge (15%): 15*1.1 = 16.5%

Item 10$
Add-on Tax (10%) 1$
Service Charge (15%) 1.65$ <----- 15% of 11$
Total: 12.65$

If you have inclusive taxes, service charge will be calculated from the amount with taxes.
If you want to be calculated from the amount without taxes, you can divide your Service Charge rate by the tax ratio.

Service Charge (15%): 15%

Item 10$
Inclusive Tax (10%) (0.91$)
Service Charge (15%) 1.5$ <----- 15% of 10$
Total: 11.5$

Service Charge (15%): 15/1.1 = 13.636%

Item 10$
Inclusive Tax (10%) (0.91$)
Service Charge (15%) 1.36$ <----- 15% of 9.09$
Total: 11.36$