Public ArcGIS MapServer endpoint for San Mateo County parcel data. URL, supported fields, and a working sample query, copy it, or open it directly in the UrbanKit parcel lookup tool.
This page is the endpoint reference. If you came here to find a specific property, the San Mateo County parcel search runs this same layer in your browser, no account and no API key.
Search San Mateo County parcelsHave a street address but not the parcel number? Find the parcel number by address.
https://gis.smcgov.org/maps/rest/services/ACRE/ACTIVE_PARCELS/MapServer/0Field by field, whether any endpoint we index for San Mateo County answers it, and the evidence for each. We only call a field restricted when there is a stated reason we can cite. Everything else here is a fact about the services we index, not a claim about the law.
| Field | Status | Basis |
|---|---|---|
| APN | Answered | Documented in a field list on an endpoint we index. Not every row is populated. |
| Owner name | Not published | The Assessor's public parcel layer (ACRE/ACTIVE_PARCELS, layer 0) has no owner-name column: its 20 fields are the APN, situs address parts, mobile home park fields, an area code and geometry measures. Where to request it. |
| Owner mailing address | Not published | The Assessor's public parcel layer carries the APN and situs address parts only; its field list has no owner mailing-address column. Where to request it. |
| Site address | Answered | Documented in a field list on an endpoint we index. Not every row is populated. |
| Geometry | Answered | Documented in a field list on an endpoint we index. Not every row is populated. |
| Land use | Not published | No endpoint we index for this county documents this field, so a query cannot ask for it. That is a fact about the services we index, not a legal restriction, and not a statement that the county holds no such record. Where to request it. |
| Zoning | Not published | No endpoint we index for this county documents this field, so a query cannot ask for it. That is a fact about the services we index, not a legal restriction, and not a statement that the county holds no such record. Where to request it. |
APNAssessor Parcel Number (APN, 9 digits, text)SITUS_ADDRSitus Address (street line, city appended)SITUS_CITYSitus Citycurl -s 'https://gis.smcgov.org/maps/rest/services/ACRE/ACTIVE_PARCELS/MapServer/0/query?where=UPPER%28SITUS_ADDR%29+LIKE+%27%25BROADWAY%25%27+AND+SITUS_CITY%3D%27REDWOOD+CITY%27&outFields=APN,SITUS_ADDR,SITUS_CITY,UNINC&returnGeometry=false&resultRecordCount=10&f=json'
https://gis.smcgov.org/maps/rest/services/ACRE/ACTIVE_PARCELS/MapServer/0/query?where=UPPER(SITUS_ADDR)+LIKE+'%BROADWAY%'+AND+SITUS_CITY='REDWOOD+CITY'&outFields=APN,SITUS_ADDR,SITUS_CITY,UNINC&returnGeometry=false&resultRecordCount=10&f=jsonOpen this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| APN | Assessor Parcel Number (APN, 9 digits, text) | YES |
| SITUS_ADDR | Situs Address (street line, city appended) | YES |
| SITUS_CITY | Situs City | YES |
| UNINC | Unincorporated Area Flag | NO |
San Mateo County, California (FIPS 06081; county seat Redwood City; Daly City, San Mateo, South San Francisco, Half Moon Bay) serves its parcels from the county's ArcGIS Server (11.1) at gis.smcgov.org/maps. The record uses the Assessor's ACRE/ACTIVE_PARCELS MapServer layer 0 (ACTIVE_PARCELS_APN): 235,492 rows on 2026-11-01. APN is 9-digit text (052367010); SITUS_ADDR is the street line with the city appended ('2200 BROADWAY, REDWOOD CITY'), SITUS_CITY is the city (null on 3,208 rows) and UNINC marks unincorporated area. NO OWNER DATA: the layer has no owner name, owner mailing address, use code or assessed value. A separate county GIS service carries an owner-names column; it is not registered, so no surface requests or shows a San Mateo owner name. maxRecordCount 2000 with pagination, NAD83 California zone III feet (a point query sets inSR=4326), CORS reflects the caller's Origin. No currency field. The old host maps.smcgov.org timed out on 2026-11-01 and is dead; third-party ArcGIS Online items still point at it. Terms: the county's GIS Terms of Use say the data is provided 'as-is', ask users to tell third parties of that disclaimer and to state 'SMC Data and San Mateo County cannot vouch for the data or analyses derived from these data.' (the credit line carries both); no commercial, resale or redistribution term and no licence text on the service. Sibling Assessor layer: ACRE/Assessor_Office_Layers layer 0 (TAXPARCELS, 239,377 rows including retired parcels, adds legal description). Verified live 2026-11-01: APN 052367010 returned 2200 BROADWAY, REDWOOD CITY; a point at Redwood City (37.48663, -122.22972) returned that parcel; UPPER(SITUS_ADDR) LIKE '%MAIN ST%' returned 237 rows; a page at offset 235,000 returned rows. Contact: countygis@smcgov.org. Credit: County of San Mateo GIS. The data is provided as-is, and San Mateo County makes no representations or warranties of any kind with respect to it. SMC Data and San Mateo County cannot vouch for the data or analyses derived from these data.
County of San Mateo, Technology Services Department, GIS Team, https://www.smcgov.org/tsd/gis
County of San Mateo GIS. The data is provided as-is, and San Mateo County makes no representations or warranties of any kind with respect to it. SMC Data and San Mateo County cannot vouch for the data or analyses derived from these data.
San Mateo County's ACTIVE_PARCELS_APN layer exposes a parcel identifier (Assessor Parcel Number (APN, 9 digits, text)) and address fields (Situs Address (street line, city appended), Situs City). Use it for address-to-PIN lookups and identifier queries. 3 of 4 listed fields accept queries; the rest are returned on read but not indexed for search. Served as an ArcGIS MapServer layer, which supports query operations but not write operations; last verified 2026-11-01.
/query?where=…&outFields=*&f=jsonto the URL. The sample query above is a working example you can paste into a browser tab to see the raw JSON response.Counties publish parcel data through their own ArcGIS Server installations, each with its own schema. One county uses APN, another uses PIN, a third uses PARCEL_ID. Some expose owner names; others keep them on a separate assessor's portal. The searchable fields list above reflects what San Mateo County actually publishes, not what you might expect from a national standard (there isn't one).
For background, see What is an APN?
gis.smcgov.org serves San Mateo County, California parcels over public ArcGIS REST, but, like most county servers, it may not send the CORS headers a browser needs for a cross-origin fetch. If a direct browser call fails, the layer still works from curl, Postman, or a server-side script; the UrbanKit parcel lookup tool proxies the request, so a search that succeeds there confirms the layer is genuinely public.
We last verified San Mateo County's MapServer layer on 2026-11-01. County GIS teams move services without notice, so if you hit a fresh 404, tell us and we'll re-check. Atlas entries are re-verified on a rolling basis.
San Mateo County's layer is hosted by the county on gis.smcgov.org. Public ArcGIS endpoints rarely rate-limit individual reads, but gis.smcgov.org can throttle heavy automated traffic at the host level. Page through results with resultOffset / resultRecordCount and request only the fields you need. There's no API key and no charge from the county.