When you add a listing in Matrix, your user ID will automatically populate to the List Agent's MLS ID field (at the bottom of the Contract tab):
If you are an admin, manager or broker for your office and are entering a listing for another agent within the office, please make sure you switch the list agent MLS ID prior to saving the listing. If not, the listing will be saved with you as the list agent instead of the intended agent.
To switch the list agent, just enter the correct agent's ID and click the Refresh button to the right of the List Agent's MLS ID field. The listing agent information should switch from yours to the agent's.
If you do not know the list agent's ID offhand, click Find a List Agent MLS ID (directly above the agent ID field). That opens a little search screen, allowing you to find them by name:
After you run the search, click the Fill link next to the appropriate agent:
That will bring you back to the Contract tab and it will populate the new agent's user ID and personal information into the list agent section: