Mich. Comp. Laws § 168.505

Sec. 505. (1) At the time an elector is applying for registration, the registration officer shall ascertain if the elector is already registered as an elector. If the elector is previously registered, the elector shall at the time of applying for registration sign an authorization to cancel a previous registration. The secretary of state shall prescribe forms for this purpose. The form may be a part of the application or a separate form. (2) An authorization to cancel that indicates a previous address in a state other than this state must be forwarded to the chief election officer of that state. Notice may be made by forwarding the separate cancellation form, by forwarding the portion of an application listing a previous place of registration, or by forwarding a list certified by the clerk containing the names of people authorizing cancellation. (3) An authorization to cancel a voter registration signed by the elector and received from another state or a notice from an election official of another state that an elector has registered in that state has the same force and effect as the notice of authorization to cancel of this state.