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City ZIP codes · California

Palo Alto, CA ZIP Codes

6 ZIP codes use the postal name Palo Alto, California (Census 2020 ZCTAs and GeoNames postal codes, October 2026): 4 residential and 2 for PO boxes or a single organization. Median household income runs from $151,609 in 94303 to $242,006 in 94301, 1.6 times as much (Census Bureau, ACS 2020-2024). Palo Alto's most populous ZIP code is 94303, with 46,879 people (ACS 2020-2024); 61% of its land is in the city of Palo Alto.

  • ACS2020-24
  • Census2020
  • GeoNames2026

Where are Palo Alto's ZIP codes?

94301: $242k median household income94303: $152k median household income94304: $154k median household income94306: $210k median household income9430494303943069430194301: $242k median household income94303: $152k median household income94304: $154k median household income94306: $210k median household income9430494303943069430194301: $242k median household income94303: $152k median household income94304: $154k median household income94306: $210k median household income94304943039430694301
The 4 residential ZIP codes named Palo Alto, shaded by median household income in national fifths (ACS 2020-2024). Select a ZIP to open it. <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are Palo Alto's ZIP codes?

The highest median household income is in 94301 ($242,006), the lowest in 94303 ($151,609). Home values run from $1,826,200 in 94303 to $2,000,000 or more in 94301.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013, B25077, B01003).

All 4 residential ZIP codes of Palo Alto

Residential ZIP codes with the postal name Palo Alto, CA, largest first (ACS 2020-2024); sort by any column
County
94303 Santa Clara County 46,879 5,555 $152k $1.83M
94306 Santa Clara County 27,183 6,654 $210k $2M+
94301 Santa Clara County 17,508 7,387 $242k $2M+
94304 Santa Clara County 5,000 1,040 $154k $2M+

Download the 6 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; 2023 Gazetteer land areas (2020 ZCTAs); town names from simplemaps US ZIP Codes (CC BY 4.0) and GeoNames (CC BY 4.0).

PO Box and single-organization ZIP codes in Palo Alto

2 ZIP codes named Palo Alto have no residential delivery area: post office boxes, or one organization (a large employer, an agency, a university) with its own code. The Census Bureau publishes no figures for them.

Palo Alto, CA: ZIP codes without a residential area, for PO boxes or one organization (GeoNames postal codes; USPS does not publish openly which is which)
ZIPCounty
94302Santa Clara County
94309Santa Clara County

Source: GeoNames postal codes (CC BY 4.0); a ZIP code with no Census ZCTA has no residential delivery area.

Which counties do Palo Alto's ZIP codes reach?

Palo Alto's residential ZIP codes lie in 2 counties: Santa Clara County (4 ZIP codes mainly there), San Mateo County (part of a ZIP code).

Which places do Palo Alto's ZIP codes cover?

A postal name is not a city limit. By the Census Bureau's places, Palo Alto's residential ZIP codes cover Palo Alto itself and 3 other places, each listed with the ZIP codes that have at least 5% of their land in it or hold most of the place:

Source: U.S. Census Bureau, 2020 ZCTA-to-place relationship file (shares of land).

Which first three digits do Palo Alto's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Palo Alto starts with 943.

Three-digit prefixes of Palo Alto's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Palo Alto's
PrefixSectional centerHereAll codes
943 San Francisco, CA (SCF 940) 6 7

6 of the 7 ZIP codes that start with 943 are Palo Alto's, all sorted at San Francisco, CA (SCF 940). The other one is 94305 (Stanford).

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.