ZIP Code 16051 — Portersville, PA
16051 is a standard (street delivery) ZIP code serving Portersville, Pennsylvania, in Butler 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 16051 at a glance
| ZIP code | 16051 |
|---|---|
| Primary city | Portersville |
| State | Pennsylvania (PA) |
| County | Butler FIPS 42019 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 3,119 |
| Coordinates | 40.944590, -80.141520 |
How ZIP+4 works in 16051
The four digits after the hyphen encode a delivery segment inside 16051. 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 16051 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 16051.
| ZIP | City | Distance |
|---|---|---|
| 16052 | Prospect, PA | 5 mi |
| 16037 | Harmony, PA | 6.5 mi |
| 16057 | Slippery Rock, PA | 7.6 mi |
| 16117 | Ellwood City, PA | 7.7 mi |
| 16101 | New Castle, PA | 8.2 mi |
| 16123 | Fombell, PA | 8.8 mi |
| 16001 | Butler, PA | 10.6 mi |
| 16157 | Wampum, PA | 10.8 mi |
| 16027 | Connoquenessing, PA | 10.9 mi |
| 16156 | Volant, PA | 11.3 mi |
| 16033 | Evans City, PA | 11.5 mi |
| 16160 | West Pittsburg, PA | 11.6 mi |
Questions about 16051
What is the ZIP+4 code for 16051?
16051 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 16051, you need to look up a specific street address to get them.
What city is 16051?
16051 is assigned to Portersville, Pennsylvania, in Butler 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.