Area codes · New Hampshire
603 area code: where it is and what time it is
The 603 area code serves the entire state of New Hampshire. It runs on Eastern Time (ET), and local calls inside 603 are dialed with 10 digits.
| State | New Hampshire |
| Main cities | Manchester, Concord |
| Time zone | Eastern Time (ET) |
| In service since | 1947 (one of the original area codes) |
| Overlay codes | None |
| Local dialing | 10 digits |
Where is the 603 area code?
The 603 area code serves the entire state of New Hampshire.
An overlay means two or more area codes share the same map. New numbers can be issued in any of them, which is why neighbors, or even two lines at one business, can have different area codes.
What time zone is the 603 area code in?
The 603 area code is on Eastern Time (ET).
The clock above shows the current local time and accounts for daylight saving time automatically. If you are scheduling a call, that is the time the person who answers will see.
Which cities use the 603 area code?
Places in the 603 area code include Manchester and Concord.
History of the 603 area code
- 603 is New Hampshire’s only area code and has been since it was assigned in October 1947.
- A second code was once expected by 2013, but number pooling and reclaimed number blocks pushed the exhaust date out to at least 2032.
- 603 moved to 10-digit local dialing in 2021 so that 988 could work as the national crisis line.
Is a call from the 603 area code a scam?
Not because of the area code. 603 is an ordinary New Hampshire area code used by homes, businesses and cellphones. Scammers can fake any caller ID, including 603 numbers, so judge the call by what the caller asks for, not by the number.
- Spoofing. Robocallers often fake a local-looking number. A 603 caller ID does not prove the call came from New Hampshire.
- Look-alike codes. Some three-digit codes that look domestic, such as 876 (Jamaica) and 809 (Dominican Republic), are international. Calling back a missed call from one can cost money. 603 is not one of them.
- What to do. Don't share codes, passwords or payment details with an unexpected caller. Report scam calls at reportfraud.ftc.gov and register your number at donotcall.gov.
Get a 603 number for your AI agent
Yes, if one is available. Every KaiCalls plan, from $10/mo, includes one phone number, and you can choose or swap its area code. From inside your agent, CallMCP's search_available_numbers tool checks live carrier inventory with area_code "603", and an extra line ($15/mo) is bought through a buy_number request that the account owner approves. Inventory changes, so a search for 603 can come back empty.
{
"name": "search_available_numbers",
"arguments": { "area_code": "603", "country": "US", "limit": 5 }
}The purchase step, buy_number, only files a request. A human on the account approves it before anything is bought, and then attach_number routes the number to your agent. The phone-number guide walks through every call. Owning a 603 number does not give your agent permission to call people there; read outbound call safety and consent first.
Other area codes
917 NY · 214 TX · 646 NY · 502 KY · 281 TX · 407 FL · 505 NM · 850 FL · 216 OH · 346 TX · 856 NJ · 757 VA · 817 TX · 724 PA · 765 IN · 540 VA · 239 FL · 607 NY · 616 MI
Sources
Facts checked against the North American Numbering Plan Administrator (NANPA) on 2026-10-30. If NANPA says something different, NANPA wins.