San Mateo County property record for 20 E 20th Ave, San Mateo, CA 94403
| Property Type | Commercial Office |
|---|---|
| Details | 9,560 sqft · built 1965 |
| Lot Size | 0.198 acres (8,640 sqft) |
| Owner | 2 Company Names on Record |
| Last Sale | $1,450,000 (Jun 2004) |
| Tax Bill | $4,330 (2025) |
| Flood Zone | Zone X (minimal risk) |
| APN | 035-235-070 |
| Primary APN | 035-235-070 |
|---|
| Stories | 2 Stories |
|---|---|
| Building Area | 9,560 sqft Gross Area |
| Basement Area | 3,527 sqft |
| Elevator | Elevator |
| Year Built | Built 1965 |
|---|---|
| Effective Year Built | Effective 1965 |
| Lot Area | 8,640 sqft (0.198 acres) |
| Street Address | 20 E 20TH AVE |
|---|---|
| City | SAN MATEO |
| State | CA |
| Zip | 94403-1319 |
| Property Category | Commercial |
| Property Type | Commercial > Office > Commercial Office |
| Local Zoning Code | E20000 |
| Legal Description | NELY 67.50 FT OF LOT 144 SAN MATEO CITY HMSTD ASSN RSM A/43 |
| Legal Subdivision | SAN MATEO CITY HMSTD ASSN |
| Legal Lot Number | 144 |
| Jurisdiction | SAN MATEO CA |
| Township / Civil Division | SAN MATEO |
| Census Block Group | 2 |
| Census Block | 2029 |
| Census Tract | 607500 |
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 Record | 2 Company Names on Record |
|---|---|
| Mailing Address | 20 E 20TH AVE, SAN MATEO, CA 94403-1319 |
| Occupancy | Owner Occupied |
| Owner Type | Company |
| Vesting | Company |
| Deed Names | 2 Names on Deed |
|---|---|
| Last Sale | Jun 2, 2004 · Amount on Record |
| Deed Sale | Jun 2, 2004 · Amount on Record |
| Deed Document Number | 2004113930 |
| Prior Transfer Date | Dec 10, 2003 |
| Prior Transfer Doc | 0000356521 |
| Record Updated | Sep 20, 2026 |
Source: San Mateo County assessment roll, as of July 15, 2026
| Type | Name |
|---|---|
| State | California |
| County | San Mateo County |
| Municipality | San Mateo City |
| Elementary School District | San Mateo-Foster City Elementary School District (KG - 08) |
| Secondary School District | San Mateo Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $2,209,440 (+2%) Land $797,617 Building $1,411,823 | |
| 2025 | $4,330.00 (+120.13%) Additional exemption filed | $2,166,119 (+4.04%) Land $781,978 Building $1,384,141 |
| 2023 | $1,967.00 (+109.7%) Additional exemption filed | $2,082,009 Land $751,614 Building $1,330,395 |
| 2022 | $938.00 |
Assessed value is set for property tax purposes and is not a market price estimate.
Source: FEMA National Flood Hazard Layer, effective September 10, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026
| FEMA Flood Zone | Zone X minimal risk |
|---|---|
| Nearest Special Flood Hazard Area | Zone AH, within 500 ft |
| Flood Insurance Requirement | Not required lenders may require it |
| Flood Insurance Cost | Premium on Record median of 15 policies |
| Nearby Flood Policies | 15 in force |
| Nearby Flood Claims | 1 (2022) |
| Most Recent Claim | Dec 2022 · Severe Winter Storms, Flooding, Landslides, And Mudslides |
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.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Not rated no burnable land within ember reach |
|---|
Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.
Source: EPA Safe Drinking Water Information System, as of September 2026
| Water System | CALIFORNIA WATER SERVICE - SAN MATEO private · serves 103,536 people · EPA ID CA4110008 |
|---|---|
| Water Source | Purchased surface water from SAN FRANCISCO REGIONAL WATER SYSTEM |
| Last State Inspection | Mar 2025 |
| Lead | 4 ppb (2023–2025) action level 15 ppb |
| Water Quality | None last 10 years |
|---|---|
| Treatment and Procedure | None last 10 years |
| Monitoring and Reporting | None 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.
Source: FCC Broadband Data Collection, based on 423 locations within half a mile, as of December 31, 2025
| Provider | Max 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 |
| Etheric Networks Fixed Wireless | 250 / 100 |
| T-Mobile Fixed Wireless | 100 / 20 |
May also be available: GeoLinks, Verizon.
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