To add/edit a (user-defined) service:
On the Applications menu, click Product Management > Product Catalog. This displays the Product Catalog window.
Click on the folder to which you want to add the new service. This displays the contents of the folder in the upper right-hand portion of the Product Catalog window.
Right-click anywhere in the upper right-hand portion of the Product Catalog window and select New > Service. Or right-click on the desired service in the upper right-hand portion of the Product Catalog window and select Edit. This displays the Add/Edit Service window.

Enter the required service details on these tabs:
Other tabs - The Attributes, Notes, Availability, and General Ledger tabs are the same as the Attributes, Notes, Availability, and General Ledger tabs for Products. See Adding Products.
Click Save.
See also:
Setting Up Equal Access Service
Tax-related Topics for Services