Area Code 410 — Baltimore, Maryland

NANP area code

410

UTC−5, UTC−4 during daylight saving

State
Maryland
Primary city
Baltimore
Time zone
Eastern
In service
1991
Overlays
443, 667

The code reaches 257 communities and 18 counties and independent cities across Maryland.

Was this call legitimate?

The area code itself carries no risk signal. 410 is assigned to Baltimore, Maryland, 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 410 territory is a plausible-looking origin for a forged 410 number, which is why one can be made to look like a neighbour to so many people. The same applies to its overlay codes 443 and 667, which serve 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

410 does not have its territory to itself. 443 and 667 cover the same ground, serving Baltimore and the rest of the 410 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 410, ranked by how many ZIP codes each holds.
CityZIP codesCounty or independent city
Baltimore42Anne Arundel County
Annapolis8Anne Arundel County
Bowie7Prince George's County
Hyattsville7Prince George's County
Laurel7Anne Arundel County
Towson5Baltimore County
Salisbury4Wicomico County
Columbia3Howard County
Ellicott City3Howard County
Glen Burnie3Anne Arundel County
Bel Air2Harford County
Chestertown2Kent County
Elkton2Cecil County
Hunt Valley2Baltimore County
Lanham2Prince George's County
Lutherville Timonium2Baltimore County
Ocean City2Worcester County
Pasadena2Anne Arundel County
Pikesville2Baltimore County
Westminster2Carroll County

237 further communities not listed. All Maryland area codes →

Each point is a community served by 410, 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 410. 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 and independent cities

Prefixes inside 410

We do not publish the NXX prefixes inside 410. 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

410 has served this territory since 1991. It eventually ran short of exchanges to hand out, and rather than split the region and make half its residents change their number, the regulator laid 443 over the same ground in 1997 and 667 over the same ground in 2012. New lines here are issued from the newer code, which is why a neighbour’s number may not start with 410.