ZIP Code 10503 — Ardsley On Hudson, NY
10503 is a standard (street delivery) ZIP code serving Ardsley On Hudson, New York, in Westchester 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 10503 at a glance
| ZIP code | 10503 |
|---|---|
| Primary city | Ardsley On Hudson |
| State | New York (NY) |
| County | Westchester FIPS 36119 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 132 |
| Coordinates | 41.026540, -73.875300 |
How ZIP+4 works in 10503
The four digits after the hyphen encode a delivery segment inside 10503. 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 10503 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 10503.
| ZIP | City | Distance |
|---|---|---|
| 10522 | Dobbs Ferry, NY | 1.1 mi |
| 10533 | Irvington, NY | 1.3 mi |
| 10502 | Ardsley, NY | 2.1 mi |
| 10964 | Palisades, NY | 2.1 mi |
| 10968 | Piermont, NY | 2.4 mi |
| 10706 | Hastings On Hudson, NY | 2.5 mi |
| 10976 | Sparkill, NY | 2.6 mi |
| 10607 | White Plains, NY | 3.4 mi |
| 10530 | Hartsdale, NY | 3.5 mi |
| 10523 | Elmsford, NY | 3.7 mi |
| 07647 | Northvale, NJ | 3.8 mi |
| 10983 | Tappan, NY | 3.8 mi |
Questions about 10503
What is the ZIP+4 code for 10503?
10503 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 10503, you need to look up a specific street address to get them.
What city is 10503?
10503 is assigned to Ardsley On Hudson, New York, in Westchester 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.