The 640 area code is an overlay serving central and southern New Jersey, layered over the 609 code across Trenton, Princeton, and the southern Jersey Shore. Introduced in 2019 to supply new phone numbers, 640 covers the exact same territory as 609. If a 640 number has appeared on your caller ID, this guide explains where it comes from, how to dial it, and how to stay safe from spoofed calls.
Quick Summary: Area Code 640 at a Glance
| Detail | Information |
|---|---|
| Area Code | 640 |
| State | New Jersey (NJ) |
| Major Cities | Trenton, Atlantic City, Princeton, Ocean City |
| Time Zone | Eastern Time (ET) |
| Country Code | +1 (USA) |
| Overlay Codes | 609 (co-located) |
Geographic Coverage & Major Cities
Area code 640 covers central and southern New Jersey, including Mercer, Atlantic, Burlington, and Cape May counties. Because it is an overlay, it shares the identical footprint of the 609 area code rather than covering a separate zone.
- Trenton – the capital of New Jersey
- Princeton – home of Princeton University
- Atlantic City – the famous casino and boardwalk resort
- Ocean City & Cape May – southern Jersey Shore destinations
As the newer code over the region, 640 numbers are common among lines set up after the original 609 numbers grew scarce.
A Brief History of Area Code 640
Area code 640 was activated in 2019 as an all-services overlay on the 609 region. The 609 code dates to 1958. An overlay adds a second area code across the same geographic area, so existing 609 customers kept their numbers while new lines could be assigned either code, under mandatory 10-digit dialing.
Time Zone & Best Time to Call
Numbers in the 640 area code use Eastern Time (ET). The region observes Daylight Saving Time, shifting from EST (UTC-5) to EDT (UTC-4) between March and November each year.
How to Dial Phone Numbers in Area Code 640
Because 640 shares its region under an overlay, the area requires 10-digit dialing on every call.
Calling within the United States or Canada
- 10-digit dialing: Include the area code – 640-XXX-XXXX.
- 11-digit dialing: You can also dial 1-640-XXX-XXXX; the leading 1 is the NANP country code.
Calling from outside the United States
- Format: [exit code] + 1 + 640 + XXX + XXXX
- From the UK, Europe, or most of Asia/Africa: 00 1 640 XXX XXXX
- From any mobile phone worldwide: +1 640 XXX XXXX
Is Area Code 640 a Scam? Safety & Protection Tips
Area code 640 is a legitimate New Jersey area code – a call from it is not fraudulent by default. However, scammers frequently spoof local codes like 640, faking the caller ID so their number appears to come from a trusted local line. Neighbor spoofing, which mimics the first six digits of your own number, is especially common.
Common scam tactics linked to this region
| Scam type | What to watch for |
|---|---|
| Government & state-agency impersonation | Callers posing as the IRS, SSA, or a state agency threatening arrest |
| Bank & card fraud alerts | Claims of suspicious activity seeking your account details |
| Lottery & casino prize scams | Fake winnings or gambling-related payouts requiring an upfront fee |
| Utility shut-off threats | Fake Atlantic City Electric or PSE&G disconnection demands |
How to report, block, and look up 640 callers
- Never share personal or financial details with an unexpected caller, however urgent they sound.
- Block the number using your phone’s built-in call-blocking feature or a reputable call-screening app.
- Look up the number with a trusted reverse phone lookup before returning any call.
- Report it to the FTC at reportfraud.ftc.gov and register at DoNotCall.gov.
Nearby & Related Area Codes in New Jersey
Area code 640 shares and borders several other New Jersey codes:
- 609 – the original central and southern NJ code that 640 overlays (see our 609 area code guide)
- 856 – the Camden area and southwest New Jersey to the west (see our 856 area code guide)
- 732 & 848 – central New Jersey and the northern shore to the north (see our 732 area code guide)
- 908 – central-northern New Jersey to the north (see our 908 area code guide)
Explore more codes across the state on our New Jersey area codes hub, or browse every prefix in our US area codes directory.
↑ See the complete list of All US Area Codes by State – every area code across all 50 states in one directory.
Explore Neighboring States
Researching area codes just across the state line? Start with these codes in the states that border New Jersey:
Frequently Asked Questions About Area Code 640
Where is the 640 area code located?
Area code 640 covers central and southern New Jersey, including Trenton, Princeton, and Atlantic City, as an overlay of the 609 code. It operates on Eastern Time.
What is the difference between 640 and 609?
There is no geographic difference. 640 overlays the exact same territory as 609; it was added in 2019 simply to supply more phone numbers.
Is 640 a landline or cell phone area code?
Both. Area code 640 serves landlines, mobile phones, and VoIP numbers throughout central and southern New Jersey.
Should I answer a call from an unknown 640 number?
If you are not expecting the call, let it go to voicemail. Legitimate callers leave a message, while spoofed or robocall numbers usually will not. Verify any unfamiliar number with a reverse lookup before calling back.
Related 640 Guides
- Worried about spam or robocalls? Browse our Scam Alerts directory.