New Jersey · Eastern Time
640 Area Code
Area code 640 is in New Jersey, serving central and southern New Jersey: Trenton, Princeton, Atlantic City and the Jersey Shore south. It is in the Eastern Time zone. It shares its territory with overlay code 609, so 10-digit dialing is required.
Last updated October 1, 2026 · Source: NANPA
Where is the 640 area code?
640 is a New Jersey area code covering central and southern New Jersey: Trenton, Princeton, Atlantic City and the Jersey Shore south. In the wider directory it sits in the Northeast region.
Cities in the 640 area code
- Trenton
- Hamilton
- Atlantic City
- Princeton
- Ewing
- Lawrence
- Egg Harbor Township
- Galloway
- Willingboro
- Pleasantville
- Ocean City
- Wildwood
- Cape May
- Mount Holly
Counties served by 640
Mercer County, Atlantic County, Cape May County, Burlington County and Ocean County.
640 overlay codes and dialing
The 640 territory is covered by an overlay of 2 area codes: 609, 640. All of them serve the same geographic area, and the original code is 609. Because more than one code covers the same ground, 10-digit dialing is mandatory — you must dial the area code for every local call. New phone lines may be assigned any of these codes.
History of the 640 area code
640 went into service on September 17, 2018 as an overlay of 609, relieving number exhaustion in the Trenton area. Rather than splitting the region, the overlay lets existing customers keep their numbers while new lines draw from the added code. Learn more in our overlay guide.
Is 640 a scam or spam risk?
640 is a legitimate geographic area code, not a premium or toll line, so a call from it costs you nothing extra. That said, scammers frequently spoof real local area codes to look familiar on caller ID. A genuine 640 number on your screen is no guarantee the caller is in Trenton, NJ or trustworthy. See spam & scam-risk area codes for how spoofing works and how to respond.
Other New Jersey area codes
Explore more
See every code in New Jersey, compare codes across the Northeast region, or view all Eastern Time codes. You can also browse the 6XX block or the complete numeric list of US area codes.
New to how this all works? Start with how area codes work, then read up on overlays, 10-digit dialing, and spam & scam-risk codes. To check another number, use the area code lookup tool.
Quick answers
640 area code FAQ
Where is the 640 area code?
The 640 area code is in New Jersey, covering central and southern New Jersey: Trenton, Princeton, Atlantic City and the Jersey Shore south, in the Northeast region.
What cities are in the 640 area code?
Cities in the 640 area code include Trenton, Hamilton, Atlantic City, Princeton, Ewing, Lawrence, Egg Harbor Township, Galloway, Willingboro and Pleasantville.
What time zone is 640 in?
640 is in the Eastern Time zone.
What is the overlay for the 640 area code?
640 shares its territory with 609. Both codes (609, 640) serve the same area, so 10-digit dialing is required for every call.
When did the 640 area code start?
640 went into service on September 17, 2018 as an overlay of 609.
Do I have to dial 10 digits for 640?
Yes. Because 640 is an overlay area, you must dial the full 10-digit number (area code + 7 digits) for every call.
Is 640 a toll-free or premium code?
No. 640 is a standard geographic area code, so calling it costs the same as any local or long-distance call on your plan. Toll-free calls use 800, 888, 877, 866, 855, 844 or 833.