603 Area Code — New Hampshire
603 is a North American Numbering Plan area code for New Hampshire, the United States. It covers about 1,394,951 people in 253 towns and 281 ZIP codes, including Manchester, Nashua and Concord.
| Field | Value |
|---|---|
| Area code | 603 |
| Country | United States (+1) |
| State / province | New Hampshire |
| Type | Standalone (no other NANP code covers the same towns) |
| Time zone | Eastern |
| Population covered | 1,394,951 |
| Towns covered | 253 |
| ZIP codes | 281 |
| Approx. centre | 43.393, -71.564 |
Where area code 603 is used
Area code 603 is assigned to New Hampshire, the United States, inside the North American Numbering Plan. Numbers in the code are written (603) NXX-XXXX at home and +1 603 NXX-XXXX when dialled from outside Canada and the United States. Since the NANP moved to 10-digit dialling you must always include the area code, even for a local call.
Towns and cities in area code 603
The 253 towns below are the largest in the 603 footprint, ranked by population. Every one of them links to its own page with the full list of area codes and ZIP codes for that town.
| Town | County | Population | ZIP codes |
|---|---|---|---|
| Manchester | Hillsborough County | 120,101 | 8 |
| Nashua | Hillsborough County | 91,294 | 5 |
| Concord | Merrimack County | 50,566 | 4 |
| Derry | Rockingham County | 34,474 | 1 |
| Dover | Strafford County | 33,440 | 3 |
| Rochester | Strafford County | 33,144 | 4 |
| Salem | Rockingham County | 30,964 | 1 |
| Merrimack | Hillsborough County | 28,176 | 1 |
| Londonderry | Rockingham County | 26,327 | 1 |
| Hudson | Hillsborough County | 25,557 | 1 |
| Keene | Cheshire County | 25,065 | 2 |
| Bedford | Hillsborough County | 23,746 | 1 |
Counties covered
| County | ZIP codes |
|---|---|
| Rockingham County | 44 |
| Hillsborough County | 39 |
| Grafton County | 39 |
| Merrimack County | 31 |
| Carroll County | 30 |
| Cheshire County | 27 |
| Strafford County | 20 |
| Belknap County | 18 |
| Sullivan County | 17 |
| Coos County | 15 |
| Oxford County | 1 |
Nearby area codes
How to dial area code 603
- Within North America: 603 + 7-digit number (603-NXX-XXXX). The leading 1 is optional on a mobile phone and required on most landlines for long-distance.
- From abroad: your country's international prefix, then 1, then 603, then the 7-digit number — for example 00 1 603 NXX-XXXX from most of Europe.
Frequently asked questions
What area code is 603?
603 is a North American Numbering Plan area code assigned to New Hampshire, the United States. It covers about 1,394,951 people in 253 towns.
Is 603 a US or Canadian area code?
603 is a United States area code. Canada and the United States share the +1 country code, so both are part of the same numbering plan.
What time zone is area code 603 in?
Area code 603 is in the Eastern time zone.
Do I have to dial 10 digits?
Yes. Every NANP call now requires the area code plus the seven-digit number, even for a local call.