Interpayments is able to accurately estimate the Transaction Fee that can be included in an ecommerce order, subscription, or recurring charge system. The non-identifying information required to calculate a Transaction Fee is the order amount, delivery address region (ZipCode), and the first six or eight digits of the credit card number.

Interpayments is integrated with our Order Entry system, our Form Code Lander Package, and our API and you can choose any of these ways that works best for you.


  • There are times when using Interpayments via API that the surcharge total is not known until after the transaction has been processed. Interpayments cannot charge more than 4% surcharge on qualifying cards/customers.

  • If you get an "Unknown Response" from the Order Surcharge API, you must dispaly a generic message to your customers stating that they will get charged up to 4% surcharge on this transaction. If you get a value that is greater than 0, you must display that Transaction Fee to the customer.

NOTE - You need to work with Interpayments to register the mids you want to take surcharge on. They will provide you with InterPayments Processor Ids to map to your gateways in your gateway list.

InterPayments Setup

Navigate to Admin > Plugins > Tax Services hover over the Interpayments plugin and hit the green Activate button.


  • Enter your Merchant Token, which is provided by Interpayments, in the MerchantToken field. Be sure to hit the blue Update button to save your Merchant Token.

  • After defining your Merchant Token, click the green Route button in the Merchant Account Routing Section to route the gateways on your gateway list with your Interpayments Processor Ids.

  • In the Merchant Routing Section you will see a drop down containing a list of the gateways you’ve added. Below that is another box where you will enter your Interpayments Processor Ids. Use this section to properly tie your Konnektive Mids to the Processor Id's provided to you from Interpayments.

  • Be sure hit the green Create button to create the Merchant Route.