603 area code
Manchester area, Eastern Time.Area code 603 covers Manchester, Nashua, Concord and 145 more places in New Hampshire, on Eastern Time.
Right now in Manchester
Eastern Time (EST, UTC-5; EDT, UTC-4 in summer)
Calling hours: Every day, 8 AM to 9 PM (the federal rule)
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Where 603 numbers come from
Numbers are issued by rate center, a billing area named for its main town. 603 has 148. Each one's share is how many 603 numbers start there. Its biggest metro area is Boston-Cambridge-Newton, MA-NH.
- Manchester11%
- Nashua8%
- Concord5%
- Derry4%
- Dover4%
- Portsmouth4%
- Merrimack3%
- Salem3%
- Laconia3%
- Keene2%
- Rochester2%
Also: Exeter, Milford, Plymouth, Suncook, Claremont, Hampton, Hanover, Lebanon, West Lebanon, Durham, Plaistow, Bedford + 125 more
Share of exchanges (blocks of 10,000 numbers). Source: NANPA rate center and exchange reports, November 10, 2026
When can you call a 603 number?
Sales calls to homes and cell phones have legal hours, set by the federal rule. Hold every 603 number to them, since you can't tell a work line from a personal cell.
What applies to 603Every day, 8 AM to 9 PM
- Federal (TCPA and FTC rule)Every day, 8 AM to 9 PMCalls to residential and mobile numbers. Most calls to businesses are exempt from the FTC's rule.47 CFR 64.1200(c)(1); 16 CFR 310.4(c) (opens in a new tab)
Local time comes from the area code, not from where the person is today. Mobiles keep their number when they move. Calling hours here are a guide, not legal advice. Every state's calling hours, with sources
The 603 area code
603 is one of the original area codes from 1947. Local calls take all 10 digits.
- 1947603 starts
Source: NANPA area code database
Calling a list of 603 numbers?
Paste it into the free phone number validator. It checks every number, finds each one's time zone and sorts the list by who you can call right now.
603 area code FAQ
What area code is 603?
603 is a New Hampshire area code for Manchester, Nashua, Concord, Derry and 144 more places.
What time zone is the 603 area code in?
Eastern Time (EST, UTC-5; EDT, UTC-4 in summer).
What are the calling hours for 603 numbers?
Every day, 8 AM to 9 PM, local time, under the federal rule.
When did the 603 area code start?
In 1947: it's one of the original area codes.
Calling 603 numbers? Reach more of them.
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