You’re probably here because you need to mail a package to a brick colonial on a winding road or you’re filling out a mortgage application for a house near the Village Green. It’s 03031. That’s the short answer. But if you’ve ever spent time in Hillsborough County, you know that a zip code in New England is rarely just a five-digit routing number for the USPS. It’s a boundary of identity, taxes, and school districts that can get surprisingly complicated once you step off the main roads.
Amherst is old. It was chartered in 1728. When the postal system started formalizing these things, Amherst wasn't just another suburb; it was a former county seat with a massive geographic footprint. Today, the zip code for Amherst NH covers about 34 square miles of land. That is a lot of ground for one code.
Why 03031 is the Only One You’ll Use
Most towns this size have a single primary zip code. Amherst is no different in that regard. Whether you are living in the historic village center—where the homes look like they belong on a Christmas card—or out toward the Milford border, 03031 is your go-to.
It’s interesting, though. If you look at a map of southern New Hampshire, the 03031 area is squeezed between Bedford’s 03110 and Merrimack’s 03054. Sometimes, GPS systems get a little confused near the borders, especially around the Souhegan River or the edges of the Ponemah Bog. I’ve seen delivery drivers end up three miles away because a "Road" in Amherst shares a name with a "Street" in a neighboring town. Honestly, it’s a classic New Hampshire headache.
The PO Box "Secret" at the Village Station
Here is something people often miss. There is a specific post office located at 4 Main Street. It’s right in the heart of the village. If you have a PO Box there, your mail is handled differently than the rural carriers delivering to the suburban developments off Route 101A.
While the physical zip code remains 03031, the logistics of the Village post office are a throwback. It’s one of those places where the postmaster might actually know your name. In a world of automated sorting facilities in Manchester, this tiny hub keeps the town's historic soul alive.
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Navigating the Border Confusion
Amherst is shaped like a jagged puzzle piece. Because of this, the zip code for Amherst NH occasionally overlaps in people's minds with Mont Vernon or Merrimack.
For example, there are sections of town near the northern border where you might have an Amherst mailing address but find yourself closer to the amenities of New Boston. This matters for more than just mail. It impacts your car insurance rates. It impacts your property taxes—which, let's be real, are a frequent topic of conversation at the local Moulton's Market.
Actually, the tax maps are the best way to verify if you're truly in the 03031 zone. The town uses a specific GIS (Geographic Information System) mapping tool. If you are ever in doubt about a property line or whether a specific lot falls under Amherst's jurisdiction or Bedford's, check the Hillsborough County Registry of Deeds. Don't just trust a Google Maps pin. Pins move. Deeds don't.
The Economics of 03031
Living in the 03031 zip code carries a certain weight in the New Hampshire real estate market. It’s consistently ranked as one of the wealthier areas in the state. According to recent US Census Bureau data, the median household income in this zip code significantly outpaces the national average.
What does that mean for you?
Higher home values.
Strict zoning laws.
A lot of preserved open space.
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The town works hard to keep its rural character. You won't find many massive apartment complexes or neon-lit strip malls once you get off the 101A corridor. The 03031 code is synonymous with "quiet."
Beyond the Five Digits: The +4 Extension
You’ve seen them. Those four extra numbers after the zip code. $03031-XXXX$.
Most people ignore them. Don't. If you’re sending something critical—like a tax payment or legal documents—using the +4 extension ensures it skips the manual sorting bins. In Amherst, these extensions are broken down by specific neighborhood sectors. The village has one set, the Horace Greeley highway area has another, and the more rugged terrain toward Baboosic Lake has its own.
Common Mistakes When Using the Zip Code for Amherst NH
People mix up Amherst, NH with Amherst, MA all the time. It sounds silly, but it happens.
Amherst, MA is 01002.
Amherst, NH is 03031.
If you get these wrong, your mail is going to take a scenic tour of New England that it doesn't need to take. Another thing: don't confuse Amherst with Mont Vernon. They share a school district (Souhegan), but they have distinct identities and distinct zip codes. Mont Vernon is 03057. If you use 03031 for a Mont Vernon address, it’s probably getting sent back to the sender after a week of sitting on a shelf.
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Why Data Accuracy Matters in 2026
We live in an era of hyper-local data. When you type the zip code for Amherst NH into a weather app or a food delivery service, you’re triggering a cascade of algorithms. In Amherst, because the geography is so spread out, the weather at the top of Chestnut Hill can be five degrees colder than the weather down by the Nashua line.
Using the correct zip code ensures you’re getting the right alerts. It also ensures that the "Find a Doctor" tool on your insurance website doesn't send you to someone 40 miles away just because they happen to be "nearby" in a straight line across the mountains.
Practical Steps for Residents and Newcomers
If you are moving to the area or managing property within the 03031 boundary, keep these points in mind to ensure everything runs smoothly:
- Verify your 911 address: New Hampshire is strict about E911 addresses. Ensure your house number is clearly visible from the road, as rural Amherst driveways can be long and confusing for emergency services using GPS tied to the 03031 code.
- Check the School District Boundaries: Just because your mailing address says 03031 doesn't automatically mean your kids go to Clark-Wilkins. While usually true, always verify with the SAU 39 office, especially if you are on the very edge of the town line.
- Update your Voter Registration: Zip codes are for mail, but voting is for precincts. Make sure your registration reflects your physical residency in Amherst to avoid issues at the polls during the next primary.
- Use the USPS Look-Up Tool: For the most accurate +4 extension, use the official USPS Zip Code Lookup. Input your specific street address to get the exact routing code.
- Note the 101A Business Corridor: If you are a business owner on the Amherst side of the "Miracle Mile" (Route 101A), ensure your marketing materials explicitly state 03031 to differentiate your business from those in Nashua or Milford.
Amherst is a place defined by its history and its landscape. The zip code 03031 is just the digital handshake that connects this 18th-century town to the modern world. Whether you’re heading to the Fourth of July parade on the green or just trying to get a package delivered on time, knowing the nuances of this specific New Hampshire corner makes life a whole lot easier.