ZIP Code 01431 — Ashby, MA
01431 is a standard (street delivery) ZIP code serving Ashby, Massachusetts, in Middlesex 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 01431 at a glance
| ZIP code | 01431 |
|---|---|
| Primary city | Ashby |
| State | Massachusetts (MA) |
| County | Middlesex FIPS 25017 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 3,211 |
| Coordinates | 42.676520, -71.823220 |
How ZIP+4 works in 01431
The four digits after the hyphen encode a delivery segment inside 01431. 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 01431 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 01431.
| ZIP | City | Distance |
|---|---|---|
| 01474 | West Townsend, MA | 3.7 mi |
| 01430 | Ashburnham, MA | 5.2 mi |
| 03071 | New Ipswich, NH | 5.6 mi |
| 03048 | Greenville, NH | 5.7 mi |
| 01420 | Fitchburg, MA | 6.3 mi |
| 01469 | Townsend, MA | 6.7 mi |
| 01462 | Lunenburg, MA | 7.9 mi |
| 03033 | Brookline, NH | 9.1 mi |
| 01473 | Westminster, MA | 9.5 mi |
| 01440 | Gardner, MA | 10.3 mi |
| 03084 | Temple, NH | 10.6 mi |
| 03086 | Wilton, NH | 10.8 mi |
Questions about 01431
What is the ZIP+4 code for 01431?
01431 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 01431, you need to look up a specific street address to get them.
What city is 01431?
01431 is assigned to Ashby, Massachusetts, in Middlesex 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.