ZIP Code 18951 — Quakertown, PA
18951 is a standard (street delivery) ZIP code serving Quakertown, Pennsylvania, in Bucks 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 18951 at a glance
| ZIP code | 18951 |
|---|---|
| Primary city | Quakertown |
| State | Pennsylvania (PA) |
| County | Bucks FIPS 42017 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 36,568 |
| Coordinates | 40.452940, -75.338330 |
How ZIP+4 works in 18951
The four digits after the hyphen encode a delivery segment inside 18951. 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 18951 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 18951.
| ZIP | City | Distance |
|---|---|---|
| 18955 | Richlandtown, PA | 2.5 mi |
| 18935 | Milford Square, PA | 3.3 mi |
| 18970 | Trumbauersville, PA | 3.6 mi |
| 18036 | Coopersburg, PA | 4.7 mi |
| 18960 | Sellersville, PA | 6.2 mi |
| 18944 | Perkasie, PA | 6.9 mi |
| 18034 | Center Valley, PA | 7.4 mi |
| 18081 | Springtown, PA | 8.1 mi |
| 18962 | Silverdale, PA | 8.3 mi |
| 18930 | Kintnersville, PA | 8.4 mi |
| 18054 | Green Lane, PA | 8.7 mi |
| 18073 | Pennsburg, PA | 8.7 mi |
Questions about 18951
What is the ZIP+4 code for 18951?
18951 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 18951, you need to look up a specific street address to get them.
What city is 18951?
18951 is assigned to Quakertown, Pennsylvania, in Bucks 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.