County
San Mateo County
San Mateo County has an estimated 2025 population of 743,568 across about 448.603 square miles of land. The county handles work tied to parcels, records, elections, health, and countywide services. Cities inside it still set many permit and local-service rules.
Starting point
County offices handle the countywide work.
Start with county offices for records, taxes, elections, public health, social services, sheriff services, and work on unincorporated land. Court cases go through the state court system, including the superior court serving the county.
What changes the answer: Cities inside the county can still control city permits, local code, utilities, business licenses, and city-specific rules.
Countywide answer
San Mateo County smoke can arrive from far away
San Mateo County directs residents to the Bay Area AQI map for current air conditions and SMC Alert for county emergency messages on poor-air days.
Read the local noteCounty offices
Start with the task in front of you.
San Mateo County handles countywide work and services on unincorporated land. Find the task below, then open the responsible office.
- Property Open the property-tax guide
Assessed value, exemptions, tax bills, and appeals
San Mateo County assessor handles value and exemptions. The clerk of the board handles a formal value appeal. The tax collector handles the bill, payment, and penalties.
- Records Open the records guide
Deeds, birth and death records, marriage records, and name changes
San Mateo County recorder is the usual office for deeds and many public records. Vital-record access depends on the record and year. A legal name change or divorce decree can involve Superior Court.
- Property work Open local-office help
Building permits, ADUs, zoning, code, water, and septic
For an unincorporated address, start with San Mateo County planning or building. An address inside a city or town starts with that local permit counter.
- Housing Open rent and housing help
Rent rules, repairs, notices, and eviction papers
Start with a local rent, housing, or code office if one serves the address. Court papers go to the Superior Court self-help path, and the deadline on the papers keeps running.
- Household help Open the benefits guide
CalFresh, Medi-Cal, CalWORKs, General Assistance, and IHSS
San Mateo County social-services agency is the main local office. Coverage, food, cash aid, and in-home support remain separate programs with separate notices.
- Public health Open health and benefits help
Vaccines, disease reporting, health records, and local health programs
San Mateo County public health is the local health jurisdiction. Health coverage and benefits still use separate programs and offices.
- Business Open the business guide
Business setup, seller's permits, local licenses, and regulated work
State filings and tax accounts do not replace county zoning, licensing, building, fire, or health approvals for the address.
- Neighborhood services Open local-office help
Potholes, streetlights, graffiti, trash, and service requests
For a county-maintained road or service in an unincorporated area, start with San Mateo County. Caltrans, utilities, transit systems, waste haulers, and special districts can own separate reporting paths.
- School and care Open the school and care guide
School enrollment, student records, and child-care checks
The school district handles assignment and records. County offices can help with some family services, while the state licenses child-care facilities.
- Parking Open parking help
Residential, guest, overnight, and local parking permits
A local parking permit is separate from a citation, moving ticket, and toll notice. Match the permit to the address, vehicle, district, or parking facility.
- Tickets Open ticket help
Traffic court, parking citations, and toll notices
San Mateo County Superior Court handles traffic court matters. A city or issuing agency handles parking. The toll operator handles toll notices.
- Safety Open emergency checks
Emergency alerts, evacuations, smoke, roads, and power
Use the county or city alert system for local warnings. Follow the local emergency office for evacuation wording, then check the matching state fire, smoke, road, or utility update.
Official county links
Open the office that handles the task.
The county links below come from California statewide directories and official county corrections. Property and recorder links open the state directory because several county offices can share one task.
San Mateo County
City, county, and district responsibilities
County and city rules can share one address.
An address in San Mateo County can sit inside a city. It can also sit on county land outside any city. That line picks the permit desk and some local rules. It does not move every county job to city hall.
County jobs stay with the county
The county assessor sets property value. The tax collector handles bills. The recorder, elections office, benefits office, and usually the health office also stay with San Mateo County. The court serves the county but is part of the state court system.
Permits follow the city line
A city or town usually handles permits, zoning, parking, business licenses, and local code inside its lines. San Mateo County handles these jobs on county land outside a city.
Districts can cross city and county lines
Water, sewer, fire, schools, transit, trash, and flood work may belong to a special district or other provider. The parcel or service bill is often the quickest way to name that agency.
Practical notes
Office, map, permit, and paperwork notes for San Mateo County
Countywide answer · Rules and licenses · Reviewed July 22, 2026
San Mateo County planning starts with unincorporated areas
San Mateo County's Current Planning Section handles land-use planning for unincorporated areas.
Community answer · Rules and licenses · Reviewed September 15, 2026
My San Mateo keeps city service requests in one place
San Mateo residents can use My San Mateo to submit and track non-emergency city service requests, including streetlight outages, weeds, graffiti, and other local concerns.
Community answer · Cars and driving · Reviewed July 7, 2026
Bay Area bridge tolls use FasTrak, plates, or invoices
Bay Area toll bridges use automatic toll collection, with FasTrak, License Plate Account, One-Time Payment, and invoice options depending on how the vehicle is set up.
Community answer · Rules and licenses · Reviewed July 3, 2026
San Mateo County FBN filings start with ACRE
San Mateo County fictitious business name filings create a public business name record through ACRE, separate from business license and permit steps.
Community answer · Money and taxes · Reviewed July 3, 2026
San Mateo County property tax has value, accounting, and bill lanes
San Mateo County property tax questions usually start with the Assessor for value, the Controller for tax accounting, or the Tax Collector for bills and payments.
Community answer · Rules and licenses · Reviewed July 3, 2026
San Mateo County records start with the paper you need
San Mateo County Clerk-Recorder errands are easier when you first name whether you need a recorded property document, vital record, marriage service, fictitious business name, or other registration.
Stories & Notes
Stories and local context across San Mateo County
Community story · History and culture
Redwood City keeps old civic buildings in daily downtown life
Redwood City's historic downtown includes the Historic San Mateo County Courthouse, Fox Theatre, Lathrop House, and Courthouse Square, where the old center still works as a public gathering place.
Community story · History and culture
Sign Hill turns South San Francisco's old slogan into a walk
South San Francisco's Sign Hill carries the famous 'The Industrial City' sign, but the hillside is also a 65-acre open space with rare plants and habitat.
Community story · History and culture
South San Francisco's biotech story grew from an industrial city
South San Francisco is known as the birthplace of biotechnology, with Genentech's 1976 start helping shift an older industrial city into a major life-science center.
Community story · Outdoors
Coyote Point shows San Mateo's busy Bay edge
Coyote Point Recreation Area brings together Bay views, a marina, marsh habitat, a beach promenade, windsurfing, playgrounds, CuriOdyssey, picnic areas, and SFO planes overhead.
Community story · History and culture
The Cow Palace gives Daly City a big Bay Area memory
The Cow Palace in Daly City began in 1941 and still carries a mix of rodeo, concert, sports, convention, and community history near the San Francisco line.
Community story · History and culture
Atherton began as Fair Oaks, a quiet rail stop for estate country
Atherton's story starts with Fair Oaks, the San Francisco-to-San Jose rail line, large country estates, and Holbrook-Palmer Park's surviving estate buildings.
Community story · History and culture
Bay Meadows still explains a big piece of San Mateo
The former Bay Meadows racetrack site shows why part of San Mateo now mixes housing, offices, shops, parks, and Caltrain access in one busy rail-side area.
Community story · History and culture
Half Moon Bay turns pumpkin season into a Main Street event
Half Moon Bay's pumpkin festival, weigh-off, farm fields, and coastal Main Street make the town's fall identity easy to see.
- 2025 population
- 743,568
- Land area
- 448.603 sq mi
- Water area
- 292.36 sq mi