Mendocino County, CA Home Business: Signage Rules (2026)

Signage for a home business in the unincorporated inland county is governed jointly by Chapter 20.184 (Sign Regulations) and the home-occupation standards in Chapter 20.156 of Title 20, Division I. Because a home occupation must remain clearly incidental and secondary to the residential use and may not change or disturb the residential or rural character of the premises or its surroundings, advertising and signage at the dwelling are expected to be modest and non-commercial in appearance. Chapter 20.184 contains the specific sign standards (including allowed types, sizes, and any permit thresholds) that apply across the inland zoning districts; residentially zoned parcels are subject to the most restrictive sign limits, and a sign permit may be required depending on size and type. Off-premises and illuminated commercial signage typical of storefront businesses is generally not consistent with the home-occupation character standard. Operators should confirm the exact dimensional limits and whether a sign permit is needed with the Planning and Building Services Department before installing any home-business sign, since posting an oversized or commercial sign can jeopardize the home-occupation status of the business.