603 Area Code
Covers Manchester and nearby communities in New Hampshire.
(603) 555-0142Area code 603 map
Interactive coverage map for area code 603, centered on Manchester, New Hampshire
42.9956, -71.4548
Open in OpenStreetMapArea code 603 coverage map — centered on Manchester. Shaded area shows the approximate reach around the primary city.
Area code 603 is a telephone area code in New Hampshire, anchored on Manchester. It reaches roughly 198,000 people across places such as Manchester, Nashua, Derry, Dover and more. The region observes Eastern time, so a number like (603) 555-0142 is on that clock right now. On the ground it spans Hillsborough, Rockingham, Strafford and nearby counties. It is not currently paired with an overlay code. Local calls inside the 603 area can generally be placed with ten digits, and you do not need a leading 1 for domestic calls. On this page you'll find a live local clock for Manchester, an interactive coverage map, the cities and counties 603 serves, its overlay and neighboring codes, and tips on spotting 603 spam calls.
Cities covered by 603
Cities & neighborhoods
- Manchester
- Nashua
- Derry
- Dover
- East Concord
- Keene
- Portsmouth
- Rochester
Counties
- Hillsborough
- Rockingham
- Strafford
- Cheshire
Looking for the broader picture? See all New Hampshire area codes.
Nearby & overlay area codes
Is a call from 603 a scam?
Area code 603 serves Manchester and the surrounding area, so most calls are ordinary local and business traffic. As everywhere, spam and robocalls do use 603 numbers, frequently by spoofing a local-looking caller ID to boost pickup rates. The area code itself tells you nothing about who is really calling, so judge the call by what's said, not the number.
Red flags to watch for
- Pressure to act right now, or threats of arrest, fines, or service being cut off.
- Requests to pay with gift cards, wire transfer, crypto, or a payment app.
- Asking for passwords, one-time codes, your SSN, or full card/bank numbers.
- A robocall or recording, or a number that won’t let you call back.
When unsure, hang up and call the organization back on a number you look up yourself.
Calling a 603 number from abroad
Every 603 number is a US/Canada +1 number. From a mobile anywhere, the simplest approach is to dial it in international format:
+1 603 555-0142If your phone can’t dial the +, replace it with your country’s exit code, then 1, then the number:
- UK, Germany, France & most of Europe
00 1 603 555-0142 - Australia
0011 1 603 555-0142 - Japan
010 1 603 555-0142 - Mexico
00 1 603 555-0142
Within the US and Canada you don’t need any of this — just dial the ten digits 603 555-0142.
Reverse phone lookup
Check any US or Canada number to see whether it's a working line, which carrier it sits on, whether it's mobile, landline or VoIP, and roughly where it's registered.
Shows carrier, line type and location. Owner name isn't available here.
Results are for personal, informational use only and may not be used for employment, credit, housing or tenant-screening decisions.
Area code 603: frequently asked questions
Where is the 603 area code located?
The 603 area code is located in New Hampshire, centered on Manchester. It covers Hillsborough, Rockingham, Strafford, Cheshire and nearby communities including Manchester, Nashua, Derry, Dover, East Concord, Keene.
What time zone is 603 in?
Area code 603 is in the Eastern time zone (UTC-5 (EST) / UTC-4 (EDT)). You can see the exact current local time for Manchester on the live clock above.
What cities use area code 603?
Cities and areas that use 603 include Manchester, Nashua, Derry, Dover, East Concord, Keene. Its primary city is Manchester, NH.
Do I need to dial 1 before 603?
You generally do not need to dial a leading 1 for domestic calls to 603. Ten-digit dialing (the 603 code plus the seven-digit number) is the safest habit.
Is 603 a toll-free or scam number?
No — 603 is a normal geographic area code for Manchester, not a toll-free code (toll-free codes are 800, 833, 844, 855, 866, 877 and 888). A 603 number is not inherently a scam, but the code can be spoofed. See the spam-call section above for how to tell.
What are the overlay area codes for 603?
Area code 603 does not currently have an overlay code; it is not layered on top of another code in the same area.