ZIP Code 17584 — Willow Street, PA
17584 is a standard (street delivery) ZIP code serving Willow Street, 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 17584 at a glance
| ZIP code | 17584 |
|---|---|
| Primary city | Willow Street |
| State | Pennsylvania (PA) |
| County | Lancaster FIPS 42071 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 11,646 |
| Coordinates | 39.959810, -76.264630 |
How ZIP+4 works in 17584
The four digits after the hyphen encode a delivery segment inside 17584. 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 17584 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 17584.
| ZIP | City | Distance |
|---|---|---|
| 17568 | Refton, PA | 1.8 mi |
| 17560 | New Providence, PA | 3.9 mi |
| 17602 | Lancaster, PA | 3.9 mi |
| 17579 | Strasburg, PA | 4.5 mi |
| 17504 | Bausman, PA | 5.6 mi |
| 17565 | Pequea, PA | 5.8 mi |
| 17603 | Lancaster, PA | 5.9 mi |
| 17551 | Millersville, PA | 6 mi |
| 17576 | Smoketown, PA | 6.3 mi |
| 17516 | Conestoga, PA | 6.7 mi |
| 17572 | Ronks, PA | 6.9 mi |
| 17532 | Holtwood, PA | 7.2 mi |
Questions about 17584
What is the ZIP+4 code for 17584?
17584 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 17584, you need to look up a specific street address to get them.
What city is 17584?
17584 is assigned to Willow Street, 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.