ZIP Code 01561 — South Lancaster, MA
01561 is a standard (street delivery) ZIP code serving South Lancaster, 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 01561 at a glance
| ZIP code | 01561 |
|---|---|
| Primary city | South Lancaster |
| State | Massachusetts (MA) |
| County | Worcester FIPS 25027 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Coordinates | 42.445810, -71.688450 |
How ZIP+4 works in 01561
The four digits after the hyphen encode a delivery segment inside 01561. 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 01561 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 01561.
| ZIP | City | Distance |
|---|---|---|
| 01510 | Clinton, MA | 2.3 mi |
| 01523 | Lancaster, MA | 2.5 mi |
| 01740 | Bolton, MA | 4.2 mi |
| 01564 | Sterling, MA | 4.3 mi |
| 01503 | Berlin, MA | 5.1 mi |
| 01505 | Boylston, MA | 6.4 mi |
| 01453 | Leominster, MA | 6.4 mi |
| 01451 | Harvard, MA | 6.8 mi |
| 01434 | Devens, MA | 7 mi |
| 01583 | West Boylston, MA | 7.2 mi |
| 01749 | Hudson, MA | 8.2 mi |
| 01532 | Northborough, MA | 8.7 mi |
Questions about 01561
What is the ZIP+4 code for 01561?
01561 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 01561, you need to look up a specific street address to get them.
What city is 01561?
01561 is assigned to South Lancaster, 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.