ZIP Code 20121 — Centreville, VA
20121 is a standard (street delivery) ZIP code serving Centreville, Virginia, in Fairfax 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 20121 at a glance
| ZIP code | 20121 |
|---|---|
| Primary city | Centreville |
| State | Virginia (VA) |
| County | Fairfax FIPS 51059 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 27,788 |
| Coordinates | 38.817500, -77.460150 |
How ZIP+4 works in 20121
The four digits after the hyphen encode a delivery segment inside 20121. 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 20121 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.
Other ZIP codes in Centreville
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 20121.
| ZIP | City | Distance |
|---|---|---|
| 20120 | Centreville, VA | 2.8 mi |
| 20109 | Manassas, VA | 4.1 mi |
| 20124 | Clifton, VA | 4.5 mi |
| 20111 | Manassas, VA | 5 mi |
| 20110 | Manassas, VA | 5.1 mi |
| 20151 | Chantilly, VA | 5.5 mi |
| 22033 | Fairfax, VA | 5.7 mi |
| 22035 | Fairfax, VA | 5.9 mi |
| 22030 | Fairfax, VA | 6.5 mi |
| 20152 | Chantilly, VA | 6.5 mi |
| 20143 | Catharpin, VA | 6.6 mi |
| 20136 | Bristow, VA | 7.5 mi |
Questions about 20121
What is the ZIP+4 code for 20121?
20121 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 20121, you need to look up a specific street address to get them.
What city is 20121?
20121 is assigned to Centreville, Virginia, in Fairfax 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.