Area Code
New Hampshire, United States
Local Time
6:18 PM
Eastern Time
Area Code
603
State / Province
New Hampshire
Country
United States
Time Zone
Eastern Time
Area code 603 covers 147 rate centers across New Hampshire. Rate centers are geographic areas used by telephone companies to determine local calling boundaries.
Use the E.164 format for clickable phone links (RFC 3966):
<a href="tel:+16035550100">+16035550100</a><a href="tel:+16035550199">+16035550199</a>Area code 603 is a North American Numbering Plan (NANP) telephone area code assigned to New Hampshire, United States. It is the sole area code assigned to New Hampshire, covering the entire state or province under a single numbering plan area.
Yes. 603 is an active North American Numbering Plan (NANP) area code, currently assigned to New Hampshire, United States. It is safe to answer or dial calls using this area code.
Area code 603 covers 147 rate centers across New Hampshire. Communities served include Alstead, Alton, Andover, Antrim, Ashland, and 142 more localities. Rate centers are the geographic building blocks telephone carriers use to determine local calling boundaries and to assign numbers when a business or individual requests a phone number in a specific city.
All numbers in the 603 area code observe Eastern Time (IANA timezone: America/New_York). Eastern Time is UTC−5 in winter (EST) and UTC−4 in summer (EDT). When placing a call to a 603 number from a different time zone, check the current local time above to avoid calling outside of business hours.
From within New Hampshire, dial the 7-digit local number directly if calling within the same rate center, or dial 1 + 603 + 7-digit number for long-distance calls within North America. From outside the US or Canada, dial your country's international exit code followed by 1 603 XXX XXXX. The country code for both the United States and Canada in NANP is +1.
Format 603 numbers using E.164 notation as required by RFC 3966: prefix with +1 and omit dashes and parentheses (e.g., +16035550100). This format ensures tel: links work correctly on all mobile browsers and VoIP apps. See the tel: URI formatting guide for complete examples.