Mich. Comp. Laws § 484.1302

Sec. 302. Two or more county boards of commissioners may jointly establish an emergency 9-1-1 district within all or part of the counties and may cause 9-1-1 service to be implemented within the emergency 9-1-1 district under this act. If 2 or more county boards of commissioners wish to jointly establish an emergency 9-1-1 district under this act, then all actions required or permitted to be taken by a county or its officials under this act shall be taken by each county or the officials of each county, and all notices required or permitted to be given to a county or its officials under this act shall be given to each county or the officials of each county.