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

Colusa County limits home-business signage tightly to preserve residential character. Zoning Code Section 44-4.90(D) provides that a home occupation must produce no evidence of its existence beyond the premises "except one sign as allowed by Section 44-3.50 (Sign Regulations)." The Sign Regulations (Section 44-3.50) apply to signs within all zones and generally require approval before a sign is installed unless the sign is on the list of signs allowed without a permit. Under Section 44-3.50.040, a permanent sign that is no greater than 8 square feet and consistent with the section's standards is allowed without a permit; such permanent signs may not be illuminated and may be no more than six feet in height if freestanding or five feet if affixed to a building. The section also allows, without a permit, one professional name plate identifying the name of a business or occupant of certain buildings up to 16 square feet, and various small directional and informational signs. Because a home occupation is limited to a single sign, a resident operating a business should keep it small, unlit, and within the residential context. Owners should confirm with the County Planning Division whether their proposed sign needs a permit.