Area code 240 covers Rockville and surrounding areas in Maryland. It was activated in 1997 as an overlay of area code 301. Today it shares its territory with overlay codes 301 and 227. For the full picture, see all Maryland area codes.
| State | Maryland |
|---|---|
| Primary city | Rockville |
| Cities also served | Rockville, Silver Spring, Germantown, Gaithersburg, Frederick, Bethesda, Hagerstown, Waldorf |
| Time zone | Eastern (UTC-5 / UTC-4 DST) |
| Year established | June 1, 1997 |
| Original 1947 NPA? | No |
| Parent code | 301 |
| Overlay codes | 301, 227 |
| Currently in use? | Yes, actively assigned |
| Ten-digit dialing required? | Yes |
Cities Served by Area Code 240
Area code 240 serves Western Maryland and the Maryland suburbs of Greater Washington, D.C., covering Montgomery, Prince George's, Frederick, Charles, St. Mary's, Allegany, Garrett, and Washington counties, plus portions of Howard, Carroll, and Anne Arundel counties, including the following cities and communities:
- Rockville
- Silver Spring
- Germantown
- Gaithersburg
- Frederick
- Bethesda
- Hagerstown
- Waldorf
Nearby area codes covering the same broader region include: 301, 227, 410, 443, 667.
How to Get a 240 Phone Number
There are three ways to get a phone number with the 240 area code, each suited to a different need:
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Browse 240 Numbers →- Buy from a premium-number specialist. Companies that hold curated inventories of specific area codes can sell you a 240 number directly, often with a one-time fee and ownership transferred to you (no recurring carrier fees). This is the option for picking a specific memorable number, or for getting an area code that most carriers won’t let you request. Browse our 240 inventory.
- Sign up with a VoIP carrier. Voice-over-IP services (such as Google Voice, OpenPhone, Grasshopper, and many others) can typically provision a 240 number on request, especially for active overlay codes. You won’t usually get to pick the specific number, but you’ll get a working line in the area code. This is the cheapest option for anyone who doesn’t need a particular number.
- Port an existing 240 number. If you already have a 240 phone number with another carrier, you can transfer it (port it) to a new service provider while keeping the number. This works for landlines, cell phones, and VoIP services, though landlines outside of Maryland sometimes can’t accept inbound ports of 240 numbers due to 911 routing rules.
Looking for a 240 number? 212areacode.com offers premium 240 numbers for Rockville, Maryland — choose your number, port it to any carrier in 3–5 business days, and pay a one-time fee with no monthly charges. Browse available 240 numbers →
Frequently Asked Questions
Is the 240 area code still in use?
Yes. 240 is actively assigned to new phone lines in Western Maryland and the Maryland suburbs of Greater Washington, D.C., covering Montgomery, Prince George’s, Frederick, Charles, St. Mary’s, Allegany, Garrett, and Washington counties, plus portions of Howard, Carroll, and Anne Arundel counties.
What is the difference between 240 and 301?
Today they share the same geographic territory in Maryland. New phone lines in the area may be assigned either code. The two codes work identically for calling, billing, and service.
What is the parent area code of 240?
Area code 240 is an overlay of 301. Both codes serve the same region of Maryland.
Can I get a 240 number if I don't live in Maryland?
Yes. Phone numbers are no longer tied to a physical address. With VoIP service or a number broker, you can hold a 240 number from anywhere in the world. The number routes to whatever device or carrier you specify.
Is 240 a scam area code?
No. 240 is a legitimate, active area code for Western Maryland and the Maryland suburbs of Greater Washington, D.C., covering Montgomery, Prince George’s, Frederick, Charles, St. Mary’s, Allegany, Garrett, and Washington counties, plus portions of Howard, Carroll, and Anne Arundel counties. Like any area code, scammers occasionally spoof 240 caller IDs, but the code itself is heavily used by real Maryland businesses, government offices, and residents.
When did area code 240 go into service?
Area code 240 went into service on June 1, 1997, as Maryland’s first overlay area code, created to relieve number exhaustion in the rapidly growing 301 territory in the Washington, D.C. suburbs.
What area codes overlap with 240?
Area codes 301 and 227 cover the exact same geographic territory as 240. Code 301 is the original 1947 code; 240 was added as an overlay in 1997; and 227 was added as a third overlay on June 14, 2023.
Do I need to dial ten digits when calling a 240 number locally?
Yes. Because 240 is an overlay sharing territory with 301 and 227, ten-digit dialing (area code + seven-digit number) is required for all local calls. The leading ‘1’ is not needed for local calls.
What cities does the 240 area code cover?
The 240 area code covers western and southern Maryland, including Rockville, Silver Spring, Germantown, Gaithersburg, Bethesda, Frederick, Hagerstown, Waldorf, Cumberland, and College Park, among many others.
