ZIP Code 17840 — Locust Gap, PA
17840 is a standard (street delivery) ZIP code serving Locust Gap, Pennsylvania, in Northumberland 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 17840 at a glance
| ZIP code | 17840 |
|---|---|
| Primary city | Locust Gap |
| State | Pennsylvania (PA) |
| County | Northumberland FIPS 42097 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 188 |
| Coordinates | 40.775370, -76.432910 |
How ZIP+4 works in 17840
The four digits after the hyphen encode a delivery segment inside 17840. 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 17840 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 17840.
| ZIP | City | Distance |
|---|---|---|
| 17834 | Kulpmont, PA | 1.8 mi |
| 17851 | Mount Carmel, PA | 1.9 mi |
| 17832 | Marion Heights, PA | 2.4 mi |
| 17943 | Lavelle, PA | 2.9 mi |
| 17945 | Locustdale, PA | 3.1 mi |
| 17921 | Ashland, PA | 4.2 mi |
| 17888 | Wilburton, PA | 4.4 mi |
| 17858 | Numidia, PA | 4.7 mi |
| 17936 | Gordon, PA | 5.2 mi |
| 17964 | Pitman, PA | 5.4 mi |
| 17920 | Aristes, PA | 6 mi |
| 17866 | Coal Township, PA | 6.2 mi |
Questions about 17840
What is the ZIP+4 code for 17840?
17840 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 17840, you need to look up a specific street address to get them.
What city is 17840?
17840 is assigned to Locust Gap, Pennsylvania, in Northumberland 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.