ZIP Code 94931 — Cotati, CA
94931 is a standard (street delivery) ZIP code serving Cotati, California, in Sonoma 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 94931 at a glance
| ZIP code | 94931 |
|---|---|
| Primary city | Cotati |
| State | California (CA) |
| County | Sonoma FIPS 06097 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 9,487 |
| Coordinates | 38.322290, -122.714970 |
How ZIP+4 works in 94931
The four digits after the hyphen encode a delivery segment inside 94931. 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 94931 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 94931.
| ZIP | City | Distance |
|---|---|---|
| 94928 | Rohnert Park, CA | 2 mi |
| 94951 | Penngrove, CA | 3.8 mi |
| 95407 | Santa Rosa, CA | 5.3 mi |
| 94952 | Petaluma, CA | 6.9 mi |
| 95405 | Santa Rosa, CA | 8.4 mi |
| 94954 | Petaluma, CA | 9.6 mi |
| 95472 | Sebastopol, CA | 9.7 mi |
| 95401 | Santa Rosa, CA | 9.7 mi |
| 95404 | Santa Rosa, CA | 10.3 mi |
| 95431 | Eldridge, CA | 10.9 mi |
| 94971 | Tomales, CA | 11.1 mi |
| 95409 | Santa Rosa, CA | 11.3 mi |
Questions about 94931
What is the ZIP+4 code for 94931?
94931 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 94931, you need to look up a specific street address to get them.
What city is 94931?
94931 is assigned to Cotati, California, in Sonoma 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.