If an agent is going to changes brokerages, before anything is done at the MLS, it needs to be determined if their listings are remaining with the agent, or at the brokerage where the listing agreements were originally signed. From there; 

• If the list agent is taking their listings to the new Brokerage, the listings at the old brokerage would need to be cancelled, and the listing agent would need to get new listing agreements. Or the listings can be transferred internally by the MLS with documentation showing the transfer of the listing signed by both Brokers.

OR

• If the broker is keeping the listings, the listing agent should be changed, prior to the current agent changing brokers, to another agent within the same brokerage .