San Mateo California ZIP Codes

San Mateo holds 5 ZIP codes, all inside one county and one postal prefix.

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the San Mateo codes above are listed without a column we would have to invent.

Scope every ZIP code recorded for San Mateo. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.

Every San Mateo ZIP code begins 944. Those first three digits identify the sectional center facility that processes mail for this part of California. No other California community draws on the 944xx range — it belongs entirely to San Mateo.

Every California ZIP prefix and the region it covers →

ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The codes below serve the same ground San Mateo occupies.

• 415 Area code 415
• 628 Area code 628
• 650 Area code 650

San Mateo California area codes in full →

Straight-line distance between place reference points, not driving distance.