Area Code 640 — Trenton, New Jersey

NANP area code

640

UTC−5, UTC−4 during daylight saving

State
New Jersey
Primary city
Trenton
Time zone
Eastern
In service
2018
Overlay
609

The code reaches 129 communities and 13 counties across New Jersey.

Was this call legitimate?

The area code itself carries no risk signal. 640 is assigned to Trenton, New Jersey, so a call from it is consistent with a real caller in that area — but the digits alone prove nothing, because they can be forged.

Caller ID is set by whoever places the call, not verified by the network. That is why neighbour spoofing works: an operation anywhere in the world can display a number that matches the area code — and often the first three digits after it — of the person being called, so the call looks local. Every community in the 640 territory is a plausible-looking origin for a forged 640 number, which is why one can be made to look like a neighbour to so many people. The same applies to its overlay code 609, which serves the same ground.

If you did not recognise the call: let it go to voicemail — a legitimate caller with real business will leave one. Do not return the call using the number shown; look the organisation up independently and call the number you found. Never confirm personal details, card numbers, or one-time codes to someone who called you, however plausible the number looked.

Codes.zone publishes no complaint counts, risk scores, or caller identities. We hold no data on individual numbers and will not estimate what we cannot source.

Local time and when to call back

Time there now

Eastern · UTC−5, UTC−4 during daylight saving

Reasonable callback window

8:00 AM – 9:00 PM

local time in Eastern

Federal rules bar telemarketing calls to a residence outside 8:00 AM–9:00 PM in the called party's own time zone. It is a sensible bound for a personal callback too — and a caller who rang you well outside it was not observing it.

Overlay codes and ten-digit dialling

640 does not have its territory to itself. 609 covers the same ground, serving Trenton and the rest of the 640 territory. An overlay is what a regulator adds when a region runs out of assignable numbers: rather than splitting the area and forcing half the residents to change their number, a second code is laid over the top and new numbers are issued from it.

The practical consequence: two neighbours on the same street can hold numbers in different area codes, so the code tells you nothing about which part of town a caller is in — and local calls must be dialled as all ten digits, because seven is no longer unambiguous.

Cities served

largest 20 by ZIP count
Communities served by area code 640, ranked by how many ZIP codes each holds.
CityZIP codesCounty
Trenton27Mercer County
Camden5Camden County
Princeton5Mercer County
Atlantic City3Atlantic County
Cherry Hill3Camden County
Absecon2Atlantic County
Joint Base Mdl2Burlington County
Millstone Township2Monmouth County
Riverton2Burlington County
Adelphia1Monmouth County
Allentown1Monmouth County
Avalon1Cape May County
Barnegat1Ocean County
Barnegat Light1Ocean County
Beach Haven1Ocean County
Beverly1Burlington County
Birmingham1Burlington County
Blackwood1Camden County
Blawenburg1Somerset County
Bordentown1Burlington County

109 further communities not listed. All New Jersey area codes →

Each point is a community served by 640, plotted from its record coordinates. The outline is the convex envelope of those points — a footprint, not a boundary.
  • Reference points and footprint
  • Not an official NANPA boundary
  • Not a USPS delivery area

Scope every community matched to 640. Source geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot), GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated . Coordinates are place reference points, not boundaries.

Counties

Prefixes inside 640

We do not publish the NXX prefixes inside 640. The assignment of prefixes to rate centres comes from LERG routing data, which is proprietary, and we will not estimate it from postal data — ZIP codes and telephone prefixes do not map onto each other. Awaiting a clean-rights NPA-NXX source.

Why this code exists

640 is the newer code here, added in 2018 over 609 (1956). The older code had run out of exchanges to assign, and an overlay avoids the alternative — splitting the region and forcing half its residents to renumber. New lines have been issued from 640 since.