The Phone field under Billing Information must have the format of ########## or ###-###-####. This phone type can be specified in NetCommunity under Administration>Sites & Settings>Phone Type Mapping>Home.

To edit the message that displays when a user enters an invalid format:
  1. Log in to NetCommunity
  2. Navigate to Site Explorer>Parts
  3. Search for the part in question and click the Pencil icon to edit it
  4. Click the Language tab
  5. From the dropdown, select Validation Messages
  6. Locate the Invalid Phone row and customize it as desired
  7. Click Save