To ensure other adjustments or discounts are excluded from the Service Charge calculation at the subtotal level, follow the steps below in EPOS Manager:
Sign in to EPOS Manager.
Type Adjustments into the Quick Search Bar and select the result.
Select the location you're making the change for, if prompted.
Click on the ... button and choose the relevant adjustment.
Select the Flags 3 tab.
Enable the tick box for 'Don't Include Other Discount Values'.
Click Save, then send changes to the required tills via Pos Updates.