ZIP Code 94070 — San Carlos, CA
94070 is a standard (street delivery) ZIP code serving San Carlos, California, in San Mateo County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 94070 at a glance
| ZIP code | 94070 |
|---|---|
| Primary city | San Carlos |
| State | California (CA) |
| County | San Mateo FIPS 06081 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 30,447 |
| Coordinates | 37.497390, -122.270210 |
How ZIP+4 works in 94070
The four digits after the hyphen encode a delivery segment inside 94070. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 94070 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 94070.
| ZIP | City | Distance |
|---|---|---|
| 94002 | Belmont, CA | 1.9 mi |
| 94065 | Redwood City, CA | 2.9 mi |
| 94061 | Redwood City, CA | 3.1 mi |
| 94063 | Redwood City, CA | 3.4 mi |
| 94403 | San Mateo, CA | 3.4 mi |
| 94404 | San Mateo, CA | 4.1 mi |
| 94402 | San Mateo, CA | 4.6 mi |
| 94027 | Atherton, CA | 4.7 mi |
| 94062 | Redwood City, CA | 5.2 mi |
| 94025 | Menlo Park, CA | 5.8 mi |
| 94401 | San Mateo, CA | 6 mi |
| 94301 | Palo Alto, CA | 7.5 mi |
Questions about 94070
What is the ZIP+4 code for 94070?
94070 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 94070, you need to look up a specific street address to get them.
What city is 94070?
94070 is assigned to San Carlos, California, in San Mateo County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.