ZIP Codes in San Mateo, CA
San Mateo uses 4 ZIP codes, all in San Mateo County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 4 San Mateo ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 94401 | standard | San Mateo | 35,295 |
| 94402 | standard | San Mateo | 25,475 |
| 94403 | standard | San Mateo | 43,276 |
| 94404 | standard | San Mateo | 35,881 |
Finding a ZIP+4 in San Mateo
Knowing which of these 4 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same San Mateo street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
Upload a CSV of San Mateo addresses and download it complete.