ZIP Code 18351 — Portland, PA
18351 is a standard (street delivery) ZIP code serving Portland, Pennsylvania, in Northampton 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 18351 at a glance
| ZIP code | 18351 |
|---|---|
| Primary city | Portland |
| State | Pennsylvania (PA) |
| County | Northampton FIPS 42095 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 546 |
| Coordinates | 40.923210, -75.100630 |
How ZIP+4 works in 18351
The four digits after the hyphen encode a delivery segment inside 18351. 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 18351 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 18351.
| ZIP | City | Distance |
|---|---|---|
| 18343 | Mount Bethel, PA | 2.3 mi |
| 07832 | Columbia, NJ | 2.5 mi |
| 07833 | Delaware, NJ | 2.6 mi |
| 18327 | Delaware Water Gap, PA | 4.8 mi |
| 18013 | Bangor, PA | 6 mi |
| 18356 | Shawnee On Delaware, PA | 6.4 mi |
| 07844 | Hope, NJ | 6.9 mi |
| 07823 | Belvidere, NJ | 7.5 mi |
| 07825 | Blairstown, NJ | 8.3 mi |
| 18301 | East Stroudsburg, PA | 8.6 mi |
| 18335 | Marshalls Creek, PA | 9.7 mi |
| 18072 | Pen Argyl, PA | 9.8 mi |
Questions about 18351
What is the ZIP+4 code for 18351?
18351 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 18351, you need to look up a specific street address to get them.
What city is 18351?
18351 is assigned to Portland, Pennsylvania, in Northampton 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.