240 Area Code
Covers Frederick and nearby communities in Maryland.
(240) 555-0142Area code 240 map
Interactive coverage map for area code 240, centered on Frederick, Maryland
39.4143, -77.4105
Open in OpenStreetMapArea code 240 coverage map — centered on Frederick. Shaded area shows the approximate reach around the primary city.
Calls tagged with area code 240 come from Frederick and nearby communities in Maryland. It reaches roughly 294,000 people across places such as Frederick, Gaithersburg, Rockville, Bowie and more. The region observes Eastern time, so a number like (240) 555-0142 is on that clock right now. On the ground it spans Frederick, Montgomery, Prince Georges and nearby counties. It is not currently paired with an overlay code. Local calls inside the 240 area can generally be placed with ten digits, and you do not need a leading 1 for domestic calls. On this page you'll find a live local clock for Frederick, an interactive coverage map, the cities and counties 240 serves, its overlay and neighboring codes, and tips on spotting 240 spam calls.
Cities covered by 240
Cities & neighborhoods
- Frederick
- Gaithersburg
- Rockville
- Bowie
- Hagerstown
- Aspen Hill
- Chillum
- Clinton
- College Park
- Cumberland
- Fairland
- Fort Washington
- Germantown
- Greenbelt
- Landover
- Montgomery Village
- North Bethesda
- North Potomac
- Olney
- Potomac
- Saint Charles
- Silver Spring
- South Laurel
- Suitland
- Waldorf
- White Oak
Counties
- Frederick
- Montgomery
- Prince Georges
- Washington
- Allegany
- Charles
Looking for the broader picture? See all Maryland area codes.
Nearby & overlay area codes
Overlay codes (same area)
These share 240’s geography — a number in either code can be on the same street.
240 has no overlay code right now.
Neighboring codes
Codes for adjacent regions and metros.
Is a call from 240 a scam?
Area code 240 serves Frederick and the surrounding area, so most calls are ordinary local and business traffic. As everywhere, spam and robocalls do use 240 numbers, frequently by spoofing a local-looking caller ID to boost pickup rates. The area code itself tells you nothing about who is really calling, so judge the call by what's said, not the number.
Red flags to watch for
- Pressure to act right now, or threats of arrest, fines, or service being cut off.
- Requests to pay with gift cards, wire transfer, crypto, or a payment app.
- Asking for passwords, one-time codes, your SSN, or full card/bank numbers.
- A robocall or recording, or a number that won’t let you call back.
When unsure, hang up and call the organization back on a number you look up yourself.
Calling a 240 number from abroad
Every 240 number is a US/Canada +1 number. From a mobile anywhere, the simplest approach is to dial it in international format:
+1 240 555-0142If your phone can’t dial the +, replace it with your country’s exit code, then 1, then the number:
- UK, Germany, France & most of Europe
00 1 240 555-0142 - Australia
0011 1 240 555-0142 - Japan
010 1 240 555-0142 - Mexico
00 1 240 555-0142
Within the US and Canada you don’t need any of this — just dial the ten digits 240 555-0142.
Reverse phone lookup
Check any US or Canada number to see whether it's a working line, which carrier it sits on, whether it's mobile, landline or VoIP, and roughly where it's registered.
Shows carrier, line type and location. Owner name isn't available here.
Results are for personal, informational use only and may not be used for employment, credit, housing or tenant-screening decisions.
Area code 240: frequently asked questions
Where is the 240 area code located?
The 240 area code is located in Maryland, centered on Frederick. It covers Frederick, Montgomery, Prince Georges, Washington, Allegany, Charles and nearby communities including Frederick, Gaithersburg, Rockville, Bowie, Hagerstown, Aspen Hill.
What time zone is 240 in?
Area code 240 is in the Eastern time zone (UTC-5 (EST) / UTC-4 (EDT)). You can see the exact current local time for Frederick on the live clock above.
What cities use area code 240?
Cities and areas that use 240 include Frederick, Gaithersburg, Rockville, Bowie, Hagerstown, Aspen Hill. Its primary city is Frederick, MD.
Do I need to dial 1 before 240?
You generally do not need to dial a leading 1 for domestic calls to 240. Ten-digit dialing (the 240 code plus the seven-digit number) is the safest habit.
Is 240 a toll-free or scam number?
No — 240 is a normal geographic area code for Frederick, not a toll-free code (toll-free codes are 800, 833, 844, 855, 866, 877 and 888). A 240 number is not inherently a scam, but the code can be spoofed. See the spam-call section above for how to tell.
What are the overlay area codes for 240?
Area code 240 does not currently have an overlay code; it is not layered on top of another code in the same area.