Permitting is highly fragmented; the City of Memphis and other incorporated municipalities operate their own building departments and issue their own permits. The Shelby County Code Enforcement office primarily handles unincorporated areas of the county. Development in unincorporated areas is subject to additional review by the Office of Planning and Development and may be impacted by flood zone regulations near the Mississippi and Wolf Rivers.
How this fits with the state
The state authority here is Tennessee Board for Licensing Contractors. The county file does not replace that — it adds the permit office, local overlays, and the actual filing path.