If your client is going to be paying in cash, you'll just want to be sure to check them out as "CASH" within one hour of the scheduled end of the appointment to prevent ExpressPay from charging the client's card.
1. Go to "Calendar" and select the appointment you wish to check out.
2. In the Appointment Details, tap "Checkout Now"
2. Confirm the charge amount, add services or products if necessary, and tap "Next"
3. Tap "Cash" and then tap "Checkout" to record the payment.