ZIP Code 17603 — Lancaster, PA
17603 is a standard (street delivery) ZIP code serving Lancaster, Pennsylvania, in Lancaster 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 17603 at a glance
| ZIP code | 17603 |
|---|---|
| Primary city | Lancaster |
| State | Pennsylvania (PA) |
| County | Lancaster FIPS 42071 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 67,571 |
| Coordinates | 40.012700, -76.352870 |
How ZIP+4 works in 17603
The four digits after the hyphen encode a delivery segment inside 17603. 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 17603 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 Lancaster
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 17603.
| ZIP | City | Distance |
|---|---|---|
| 17504 | Bausman, PA | 1.5 mi |
| 17551 | Millersville, PA | 2.6 mi |
| 17554 | Mountville, PA | 4.3 mi |
| 17601 | Lancaster, PA | 4.6 mi |
| 17582 | Washington Boro, PA | 5.3 mi |
| 17516 | Conestoga, PA | 5.5 mi |
| 17602 | Lancaster, PA | 5.6 mi |
| 17520 | East Petersburg, PA | 5.9 mi |
| 17584 | Willow Street, PA | 5.9 mi |
| 17538 | Landisville, PA | 6.2 mi |
| 17512 | Columbia, PA | 7.3 mi |
| 17606 | Lancaster, PA | 7.3 mi |
Questions about 17603
What is the ZIP+4 code for 17603?
17603 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 17603, you need to look up a specific street address to get them.
What city is 17603?
17603 is assigned to Lancaster, Pennsylvania, in Lancaster 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.