Calculate service fee Login to Neartail > click on the form to open it > Edit page will be displayed > In the Neartail Edit page, click on the Add price field icon > select Tip, click Next > Update the title "Service fee", select Percentage option, click Next > Enter the percentage for order amount and click Create. For example, you can charge 5% of the order amount as the service fee. Calculate total amount including service fee In the Neartail Edit page, click on the Add price field icon > select Net amount, click Next > select Standard calculation using NETTOTAL() formula, click Next > click Create. Please try this and confirm.