Contra Costa County, CA Rental Property Rules: Rental Registration (2026)
Key Facts
- Mandatory registration
- No general program for long-term rentals
- Rent cap
- AB 1482: 5% + CPI, 10% max
- Just cause
- AB 1482: required for covered properties
- STR registration
- TOT with Treasurer-Tax Collector
- Habitability
- CA Civil Code 1941+; Health Dept. enforcement
Summary
Unincorporated Contra Costa County does not operate a mandatory rental registration program for single-family or small multi-family rentals. Landlords are subject to state requirements including AB 1482 rent cap, Tenant Protection Act, and general business tax filings.
(a) (1) Subject to subdivision (b), an owner of residential real property shall not, over the course of any 12-month period, increase the gross rental rate for a dwelling or a unit more than 5 percent plus the percentage change in the cost of living, or 10 percent, whichever is lower, of the lowest gross rental rate charged for that dwelling or unit at any time during the 12 months prior to the effective date of the increase. In determining the lowest gross rental amount pursuant to this section, any rent discounts, incentives, concessions, or credits offered by the owner of such unit of residential real property and accepted by the tenant shall be excluded.
(2) If the same tenant remains in occupancy of a unit of residential real property over any 12-month period, the gross rental rate for the unit of residential real property shall not be increased in more than two increments over that 12-month period, subject to the other restrictions of this subdivision governing gross rental rate increase.
(b) For a new tenancy in which no tenant from the prior tenancy remains in lawful possession of the residential real property, the owner may establish the initial rental rate not subject to subdivision (a). Subdivision (a) is only applicable to subsequent increases after that initial rental rate has been established.
Full Breakdown
Unincorporated Contra Costa County has no general rental registration or rental licensing program applicable to most residential rental properties, unlike some cities within the County (such as Richmond and Concord, which have rent programs). Landlords of long-term residential rentals in unincorporated CCC are instead subject to California state law, including the Tenant Protection Act of 2019 (AB 1482) which caps annual rent increases at 5 percent plus CPI (not to exceed 10 percent) on most properties built 15+ years prior and imposes just-cause eviction standards.
Properties exempt from AB 1482 include single-family homes not owned by a corporation (with proper notice), newer construction, and certain affordable housing. 5), habitability (1941+), and source-of-income discrimination (under the California Fair Employment and Housing Act) apply. Short-term rentals (under 30 days) require transient occupancy tax (TOT) registration with the County Treasurer-Tax Collector and compliance with zoning. Mobile home parks are regulated under California Mobilehome Residency Law (MRL). The County Health Department may inspect rental housing in response to habitability complaints. Mobile home parks require permits from HCD for certain changes. A business license may be required if the landlord operates more than a threshold number of units.
Frequently Asked Questions
Do I need to register as a landlord in unincorporated CCC?
How much can I raise the rent each year?
Sources & Official References
Other rules in Contra Costa County
California rules heatmap·Compare Contra Costa County to another location·View the California rental property rules overview
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