ZIP Code 01603 — Worcester, MA
01603 is a standard (street delivery) ZIP code serving Worcester, Massachusetts, in Worcester 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 01603 at a glance
| ZIP code | 01603 |
|---|---|
| Primary city | Worcester |
| State | Massachusetts (MA) |
| County | Worcester FIPS 25027 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 20,868 |
| Coordinates | 42.243730, -71.844290 |
How ZIP+4 works in 01603
The four digits after the hyphen encode a delivery segment inside 01603. 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 01603 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 Worcester
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 01603.
| ZIP | City | Distance |
|---|---|---|
| 01611 | Cherry Valley, MA | 1.7 mi |
| 01610 | Worcester, MA | 1.8 mi |
| 01602 | Worcester, MA | 2 mi |
| 01608 | Worcester, MA | 2.5 mi |
| 01609 | Worcester, MA | 3 mi |
| 01607 | Worcester, MA | 3 mi |
| 01501 | Auburn, MA | 3.2 mi |
| 01524 | Leicester, MA | 3.9 mi |
| 01604 | Worcester, MA | 3.9 mi |
| 01605 | Worcester, MA | 4.3 mi |
| 01542 | Rochdale, MA | 4.4 mi |
| 01527 | Millbury, MA | 5.1 mi |
Questions about 01603
What is the ZIP+4 code for 01603?
01603 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 01603, you need to look up a specific street address to get them.
What city is 01603?
01603 is assigned to Worcester, Massachusetts, in Worcester 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.