Yes, there are 2 (two) features that will have a potential additional cost. 

1. Publish Clinic Coupon or Best Deal – The clinic can publish Coupon or Best Deal at a certain period of time and will be charged as advertisement cost.
2. Discount for Prepaid Treatment – Clinic can promote their non-peak hours by using Discounted Slot Schedule feature. The patient will be given a discount for every transaction in Discounted Slot Schedule. There will be an additional discount for prepaid treatment with the maximum value (US$) defined and possible reduced cost to the patient covered by Clinic Processing Fee (0-5%) might apply depends on the Clinic Subscription.