San Mateo County, CA Short-Term Rentals: Occupancy Limits (2026)
Key Facts
- Base formula
- 2 persons per bedroom rented + 2
- One-bedroom example
- Up to 4 tenants
- Children under 12
- Not counted toward the maximum
- Posting required
- Tenant limit posted inside the unit
- Code section
- Section 6401.3(6)(a)
Summary
Under Zoning Regulations Section 6401.3(6)(a), the maximum number of short-term tenants is two persons per bedroom rented plus two additional persons. Children under 12 are not counted. Renting one bedroom allows up to four tenants.
17920.3. Any building or portion thereof, regardless of zoning designation or approved uses of the building, including any dwelling unit, guestroom or suite of rooms, or the premises on which the same is located, in which there exists any of the following listed conditions to an extent that endangers the life, limb, health, property, safety, or welfare of the occupants of the building, nearby residents, or the public shall be deemed and hereby is declared to be a substandard building: (a) Inadequate sanitation shall include, but not be limited to, the following: (1) Lack of, or improper water closet, lavatory, or bathtub or shower in a dwelling unit. (2) Lack of, or improper water closets, l
Full Breakdown
San Mateo County caps short-term rental occupancy in the unincorporated Coastal Zone through a performance standard built into every permit. 3(6)(a) sets the maximum number of short-term tenants at two (2) persons per bedroom rented, plus two (2) additional persons. The ordinance gives a worked example: if one bedroom is rented, up to four short-term tenants are permitted. Children under twelve (12) years of age are not counted toward this maximum, so a family with young children can exceed the headline number on account of those children.
Because the formula is tied to bedrooms 'rented,' the limit scales with how much of the home is offered; a three-bedroom whole-home rental would allow up to eight tenants (3 x 2 + 2), and so on. 3(6)(b), a single-family STR with a maximum occupancy exceeding eight short-term tenants must provide at least two on-site parking spaces instead of one. 3(6)(g). The local contact person is expected to ensure tenants do not overcrowd the site.
Violations & Fines
Exceeding the per-bedroom occupancy cap is a violation of the permit's performance standards under Section 6401.3(6). Documented violations can lead to administrative penalties under Chapter 1.40 and, if more than two occur within a 12-month period, suspension or revocation of the permit.
Frequently Asked Questions
How many guests can stay in a one-bedroom short-term rental?
Do children count toward the occupancy limit?
Sources & Official References
Other rules in San Mateo County
California rules heatmap·Compare San Mateo County to another location·View the California short-term rentals overview
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