421 30th Ave, San Mateo, CA 94403 Property Records

San Mateo County property record for 421 30th Ave, San Mateo, CA 94403

Property Summary

Property TypeSingle Family Home
Details3 bd · 2 ba · 1,600 sqft · built 1940
Lot Size0.127 acres (5,510 sqft)
Owner2 Company Names on Record
Tax Bill$5,009 (2025)
Flood ZoneZone X (minimal risk)
APN039-313-060

Property Details

APN / Parcel Number

Primary APN039-313-060

Interior

Bedrooms3 Beds
Full Baths2 Baths
Total Rooms6 Rooms
Building Area1,600 sqft Living Area
1st Floor Area1,120 sqft
Family RoomFamily Room

Exterior

Year BuiltBuilt 1940
Effective Year BuiltEffective 1940
Lot Area5,510 sqft (0.127 acres)
Lot Dimensions110 ft deep x 50 ft wide
Garage Area220 sqft
Parking Spaces1 Parking Space

Utilities, Heating & Cooling

Cooling SystemCentral
Heating SystemCentral

Location & Zoning

Street Address421 30TH AVE
CitySAN MATEO
StateCA
Zip94403-2718
Property CategoryResidential
Property TypeResidential > Single Family > Home
Local Zoning CodeR10006
Legal DescriptionLOT 6 BLOCK 12 SAN MATEO TERRACE MAP NO 5 RSM 22/35 CITY OF SAN MATEO
Legal SubdivisionSAN MATEO TERRACE MAP NO 5
Legal Block12
Legal Lot Number6
JurisdictionSAN MATEO CA
Township / Civil DivisionSAN MATEO
Census Block Group2
Census Block2016
Census Tract607300

Owner

Source: San Mateo County records, as of July 15, 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record2 Company Names on Record
Mailing Address421 30TH AVE, SAN MATEO, CA 94403-2718
OccupancyOwner Occupied
Owner TypeCompany
VestingTrust

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names2 Names on Deed
Last Transfer DateSep 22, 2009
Transfer Doc0000126848
Record UpdatedSep 20, 2026

Tax Assessment & Valuation

Source: San Mateo County assessment roll, as of July 15, 2026

Property Jurisdictions

TypeName
StateCalifornia
CountySan Mateo County
MunicipalitySan Mateo City
Elementary School DistrictSan Mateo-Foster City Elementary School District (KG - 08)
Secondary School DistrictSan Mateo Union High School District (09 - 12)

Tax Bill & Assessment History

YearTax BillAssessed ValueAssessed Market Value
2026$335,013 (+2%) Land $176,325 Building $158,688
2025$5,009.00 (-6.04%) Homeowner's exemption$328,445 (+4.04%) Land $172,868 Building $155,577
2023$5,331.00 (+0.93%) Homeowner's exemption$315,693 Land $166,156 Building $149,537$2,152,890
2022$5,282.00

Assessed value and assessed market value are set for property tax purposes and are not market price estimates.

Flood

Source: FEMA National Flood Hazard Layer, effective September 10, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026

FEMA Flood ZoneZone X
minimal risk
Flood Insurance RequirementNot required
lenders may require it
Nearby Flood Policies2 in force
Nearby Flood Claims4 (1998–2022)
Claims Outside the SFHA4 of 4
Most Recent ClaimDec 2022 · rainfall accumulation

Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.

Wildfire

Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024

Wildfire RiskNot rated
no burnable land within ember reach

Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.

Drinking Water

Source: EPA Safe Drinking Water Information System, as of September 2026

Water SystemCALIFORNIA WATER SERVICE - SAN MATEO
private · serves 103,536 people · EPA ID CA4110008
Water SourcePurchased surface water from SAN FRANCISCO REGIONAL WATER SYSTEM
Last State InspectionMar 2025
Lead4 ppb (2023–2025)
action level 15 ppb

Violations Reported to EPA

Water QualityNone
last 10 years
Treatment and ProcedureNone
last 10 years
Monitoring and ReportingNone
last 3 years

Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.

Internet Providers

Source: FCC Broadband Data Collection, based on 716 locations within half a mile, as of December 31, 2025

ProviderMax Down / Up (Mbps)
Sonic Telecom
Fiber
10,000 / 10,000
AT&T
Fiber · Fixed Wireless, DSL in parts of the area
5,000 / 5,000
Xfinity
Cable
2,000 / 250
Astound Broadband
Cable · Fiber in parts of the area
1,500 / 50

May also be available: Etheric Networks, GeoLinks, T-Mobile.

Nearby Properties on 30th Ave

Nearby Streets

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