Multiple Third Party Designees are setup through multiple Users.  To setup multiple Users, click the User button on the 1099-Etc Main Menu, setup a new 3-character User Code and enter the information for each Third Party Designee.  Then selecting the appropriate User code will print the associated Third Party Designee information.

In A-T-F Payroll, you can enter a default User Code for each payer on the Payer>Payer Edit>Miscellaneous screen. This will always use the Third Party Designee information that is setup for this user.