Yes, users can set up sub-users on an existing account by purchasing an additional premium subscription for each additional user. 

• If you subscribed to PC*MILER Web on your own using a credit card (self-service), you can add users by clicking on My Account in the top right corner of the screen. 
• If you purchased your PC*MILER Web subscription directly through Trimble Maps, please contact your sales representative or our support team to add users.

Users on the same account share access to custom data created via ContentTools, but each user must maintain their own Application Settings and Route Options.