Hi - The formula that you have added for the order amount calculation is incorrect. Please make the following changes. Update order amount formula Login to Neartail > click on the form to open it > Edit page will be displayed > In the Neartail Edit page, click on the gear icon next to the Order Amount field > Field settings page will be displayed > click Answer > delete the existing formula in the Calculate option, enter TOTAL() and click Save. Transaction fee Currently we do not have the option to charge a different transaction fee depending on the payment method. For now, you can set up a fixed percentage to be charged as a transaction fee. In the Neartail Edit page, click on the Add price field button > select Tip, click Next > Update the title "Transaction 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 transaction fee. Calculate total amount including transaction fee In the Neartail Edit page, click on the Add price field button > select Net amount, click Next > select Standard calculation using NETTOTAL() formula, click Next > click Create.