First three digits · California
ZIP Codes Starting with
10 ZIP codes start with 948, sorted at the Oakland, CA (SCF 945) sectional center (USPS labeling list L005, effective October 1, 2026) in California: 5 residential ZIP codes across 1 county and 5 PO Box or single-organization codes (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 948 mean?
The first digit, 9, is one of ten national areas (Alaska, California, Hawaii, Oregon, Washington, American Samoa, Guam, Northern Mariana Islands, Marshall Islands, Micronesia, Palau and Armed Forces Pacific). The first three, 948, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 948 to the Oakland, CA (SCF 945) facility. The last two digits pick the delivery area. By residents, the largest town names among the 948 ZIP codes are Richmond, San Pablo and El Sobrante.
The same facility sorts 4 prefixes, 144 ZIP codes in all: 945, 946, 947, 948.
Where are the 948 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 948
| County | ||||||
|---|---|---|---|---|---|---|
| 94801 | Richmond | Contra Costa County | 33,591 | 2,920 | $82k | $609k |
| 94802 | Richmond | Contra Costa County | PO Box or unique | – | – | – |
| 94803 | El Sobrante | Contra Costa County | 27,659 | 2,158 | $118k | $784k |
| 94804 | Richmond | Contra Costa County | 44,891 | 6,914 | $91k | $632k |
| 94805 | Richmond | Contra Costa County | 14,670 | 7,866 | $111k | $792k |
| 94806 | San Pablo | Contra Costa County | 62,546 | 7,966 | $86k | $608k |
| 94807 | Richmond | Contra Costa County | PO Box or unique | – | – | – |
| 94808 | Richmond | Contra Costa County | PO Box or unique | – | – | – |
| 94820 | El Sobrante | Contra Costa County | PO Box or unique | – | – | – |
| 94850 | Richmond | Contra Costa County | PO Box or unique | – | – | – |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.