240 doesn't have its own territory. It shares the map with 301, and since 2023 with 227 as well. The three codes cover the same part of Maryland: the Washington, D.C. suburbs in Montgomery and Prince George's counties, Frederick, the western panhandle out to Garrett County, and Southern Maryland around Waldorf. A 240 number tells you a phone is in that region. It doesn't tell you which town.
The short version
| Shares territory with | 301 (since 1997) and 227 (since 2023) |
| In service since | June 1, 1997, Maryland's first overlay |
| Main communities | Bethesda, Silver Spring, Rockville, Gaithersburg, Germantown, Bowie, Frederick, Hagerstown, Waldorf |
| Local dialing | 10 digits for every local call |
| Time zone | Eastern (EST, UTC−5 / EDT, UTC−4) |
| Not covered | Baltimore, Annapolis and the Eastern Shore (410/443/667) |
Where 240 numbers are used
According to Wikipedia's description of the 301/240/227 area, it includes all of seven counties and parts of four more (Wikipedia):
- Washington suburbs: all of Montgomery County (Bethesda, Silver Spring, Rockville, Gaithersburg, Germantown, Potomac, Wheaton, Aspen Hill) and Prince George's County (Bowie, College Park and the rest of the county).
- Frederick: most of Frederick County, including the city of Frederick.
- Western Maryland: all of Washington County (Hagerstown), Allegany County (Cumberland) and Garrett County.
- Southern Maryland: all of Charles County (Waldorf) and St. Mary's County.
- Edges: western Howard County, plus small slivers of southwestern Carroll County and western Anne Arundel County.
Calvert County isn't on that list. It's often lumped in with Southern Maryland's 240/301 area, but Prince Frederick, the county seat, uses the 410/443/667 codes (zip-codes.com). Baltimore, Annapolis and the Eastern Shore are in 410/443 as well.
When the Maryland Public Service Commission announced 227 in 2023, it listed Aspen Hill, Bethesda, Bowie, Frederick, Gaithersburg, Germantown, Hagerstown, Potomac, Silver Spring, Waldorf and Wheaton as communities in the 240/301/227 region (Maryland PSC, June 2023).
How Maryland ended up with three codes in one area
1947–1991: one code for the state. 301 was one of the original 1947 area codes, and for more than four decades it covered all of Maryland.
1991: the 410 split. On November 1, 1991, Baltimore and the Eastern Shore were split off as 410. That left 301 with the western, central and southern parts of the state.
1997: 240, the first overlay. Within a few years, mainly because of cell phones and pagers in the D.C. suburbs, 301 was close to running out again. Instead of a second split, 240 was introduced on June 1, 1997 as Maryland's first overlay, and 443 followed a month later on the 410 side. Overlays were new at the time and unpopular because they required ten-digit dialing. Wikipedia notes that the phone company favored them because a split would have forced about 1.2 million people to change their numbers (Wikipedia).
2023: 227 joins. In September 2022 the Maryland PSC announced a third code for the region, because numbers in 240/301 were projected to run out in the second quarter of 2023. Starting June 14, 2023, new lines could be given 227 numbers once 240 and 301 stock ran out (Maryland PSC). So area code 227 was added as a third overlay, and three codes now share one map.
Dialing in the 240/301/227 area
Because the overlay has been in place since 1997, ten-digit dialing has been normal here for a long time. The PSC's 227 notice spells out the rules:
- Dial 10 digits (area code + number) for all local calls, within and between 240, 301 and 227.
- Dial 1 + 10 digits for long distance.
- 911 and 988 are still three digits, as are 211, 311, 411, 511, 611, 711 and 811 where they're offered.
- A local call stays local whichever of the three codes either number has.
Calls to Washington, D.C. (202) or Northern Virginia (703/571) also use the full number. The PSC also asked customers to make sure automatic dialing equipment and other systems recognize 227 as a valid area code, and to keep storing numbers in 10-digit form.
The whole region is on Eastern Time.
240, 301 or 227: does the code tell you anything?
Not much about location. Within the overlay, which code a number gets mainly depends on when it was issued:
- 301: the original code, so a 301 number may be decades old.
- 240: issued from mid-1997 onward, so it has been familiar locally for more than 25 years.
- 227: new numbers from June 2023 onward, so less familiar locally.
All three are local to Montgomery, Prince George's, Frederick, Hagerstown and Waldorf callers. A 240 number from Hagerstown and one from Bethesda look the same on caller ID.
Who's calling from a 240 number?
Usually a person or business somewhere in the region above. 240 isn't a scam area code, but because it's local to such a large population, spoofers often use 240 and 301 numbers to make a call look like it's from a neighbor. Some practical checks:
- Don't trust the caller ID alone. If a "local" caller says they're from your bank, Pepco, BGE, the county or a federal agency and wants payment or personal details, hang up. Call back on a number from your statement or the agency's website.
- Pressure is the tell. Real organizations don't demand gift cards, wire transfers or immediate payment to avoid arrest or a shutoff.
- Report it. Report fraud attempts to the Federal Trade Commission. Block repeat numbers using your carrier's or phone's blocking tools.
Getting a 240 number for a business
A 240 number makes sense if your customers are in the Maryland suburbs of D.C., in Frederick, or in Western or Southern Maryland. You don't need an office in the state. Virtual phone providers such as Rozper can assign a 240 number and ring it on whatever phones or apps your team uses.
There are two ways to get one:
- A new number. Pick one from the provider's available 240 stock, set up routing, and it's usually live the same day. Since June 2023, new numbers in the region can also come from 227 once 240 and 301 stock runs out, so 240 choices may be limited. A 227 number covers exactly the same area.
- Porting an existing number. You keep the number and switch providers. It takes longer than a new number because your current carrier has to release it. To avoid rejections, match the account name and service address to the old carrier's records, and keep the old service active until the port completes.
One region-specific setup tip: make sure your phone system, CRM and any web forms accept 227 as a valid area code. Validation lists written before 2023 often only include 240 and 301.
FAQs
Where is the 240 area code?
Western, central and southern Maryland. That means Montgomery and Prince George's counties in the D.C. suburbs, most of Frederick County, Washington, Allegany and Garrett counties in the west, and Charles and St. Mary's counties in the south. It shares this area with 301 and 227.
Is 240 the same as 301?
They cover the same territory. 301 is the original 1947 code, and 240 was added as an overlay on June 1, 1997. Calls between them are local, but you need all ten digits.
What is the 227 area code?
A third overlay on the same 240/301 region. It went into service on June 14, 2023, after 240 and 301 numbers neared exhaustion. Existing 240 and 301 numbers didn't change.
Is Baltimore or Annapolis in the 240 area code?
No. Baltimore, Annapolis, most of Anne Arundel County, Calvert County (Prince Frederick) and the Eastern Shore are in the 410/443 area. 240 covers the other side of the state.
Do I need to dial 10 digits for local calls?
Yes. Ten-digit dialing has been required in the 301/240 region since the 240 overlay started in 1997, and that hasn't changed with 227. 911 and 988 are still three digits.
What time zone is the 240 area code?
Eastern Time: UTC−5 in winter and UTC−4 during daylight saving time.
Is 240 a scam area code?
No. It's a normal Maryland area code used by ordinary households and businesses. Scammers can spoof any local code, so verify unexpected callers by calling back on a number you look up yourself.
Can I get a 240 number without being in Maryland?
Yes. A virtual 240 number can be routed to staff anywhere. If no 240 numbers are available, a 227 number covers the same area and is just as local.
