Yes. Typically, you would be asked to sign an agreement which would stipulate the terms of service and relevant fee. This is a private contract between you and your housing agent and there are contractual terms and legal obligations involved. Before signing, you should take the time to read through all the clauses of the agreement carefully and clarify any doubts you may have with your prospective agent. Should there be a need to vary any clause, you should negotiate upfront with your agent and upon mutual agreement, make necessary amendments in writing. All parties need to sign the amendments.