603 Area Code — NH
Area code 603 serves NH in the Eastern time zone, in service since 1947. The FCC has 79 unwanted-call complaints against 77 different 603 numbers on record. Look up the exact number that called you below.
Most-reported 603 numbers
Ranked by FCC unwanted-call complaints. Click a number for its full report.
603 unwanted-call complaints, last 12 months
Monthly FCC complaint volume against 603 numbers. Spikes usually mark an active robocall campaign cycling through the code.
About area code 603
- Serves
- NH
- Time zone
- Eastern
- In service since
- 1947-01-01
- Overlay
- No
Source: NANPA numbering records, refreshed weekly.
Spam calls from 603? What to know
Seeing repeated missed calls from 603 numbers you don't recognize is the classic signature of neighbor-spoofing robocall campaigns. The caller isn't necessarily in NH — spoofing software displays whatever digits the campaign chooses. Never call unknown numbers back; look them up first, and report unwanted calls to the FCC to build the public record.
Area code 603 FAQs
Where is area code 603?
Area code 603 serves NH, in the Eastern time zone. It has been in service since 1947.
Why do I keep getting calls from 603 numbers?
Robocallers use "neighbor spoofing" — displaying a number with a local area code to make you more likely to answer. A call showing area code 603 may not originate from NH at all. Look up the full 10-digit number on this site to see its complaint history before calling back.
Are 603 numbers safe to call back?
Area codes themselves are neither safe nor unsafe — 603 contains millions of legitimate lines alongside any spoofed or spam numbers. The FCC has logged 79 unwanted-call complaints against 77 distinct 603 numbers in our current data window. Check the specific number's report page before returning a missed call.