Certain customers have two separate utilities providing them service; one utility that generates the electricity and another that transmits and distributed it to the customer's home. These customers might have two separate tariffs, one from each utility. Clicking on this option would open a pop-up asking you to add two json files. Please note that only tariffs created using the Tariff Builder application can be opened again by this option.
Once you have loaded the two json files, the Tariff Builder will combine the rates from both tariffs. Verify this by clicking on the respective tabs to view the list of rates. You could choose to save this combine tariff under a new name by clicking the Save As button on the right.
Once you have created both tariffs, you can import each file from Import Tariff tab in the section shown below.