Area Code 240 Location: Maryland
Area code 240 covers the western part of Maryland, including the Greater Washington, D.C. metro area, southern Maryland, and rural western Maryland.
Counties Served by Area Code 240:
- Allegany County
- Charles County
- Garrett County
- Montgomery County
- Prince George's County
- St. Mary's County
- Washington County
- Frederick County (most of)
- Howard County (western)
- Carroll County (slivers of southwestern)
- Anne Arundel County (western slivers)
Major Cities in the 240 Service Area:
- Frederick
- Gaithersburg
- Rockville
- Bethesda
- Silver Spring
- Hagerstown
- Cumberland
- Germantown
- Potomac
- Landover
- Waldorf
Other Cities and Towns:
- Laurel
- Marlboro (Upper Marlboro)
- Mount Airy
Overlay System
Area code 240 is an overlay to area code 301. Area code 301 was the original area code for the entire state of Maryland. Area code 240 was introduced on June 1, 1997. A third overlay code, 227, was added on June 14, 2023. Ten-digit dialing is required for all calls within this region.
Area Code 240 Location Map
Area code 240 is a General Purpose Code which was placed in service on January 1, 1947.
240 Area Code Prefixes
Our reverse phone lookup will analyze the three-digit prefix of any 240 area code phone number and will show which telecommunications company and rate center it was initially assigned to. This prefix code data may help to determine the U.S. carrier, Maryland geographic region, and local calling area associated with the phone number.
Prefixes by Company
| Company |
Number of Prefixes |
| SPRINT SPECTRUM, L.P. |
54 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD |
45 |
| VERIZON MARYLAND, INC. |
42 |
| NEW CINGULAR WIRELESS PCS, LLC - DC |
41 |
| OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC |
24 |
| LEVEL 3 COMMUNICATIONS, LLC - MD |
21 |
| XO MARYLAND, LLC |
20 |
| US LEC OF MARYLAND, INC. |
16 |
| GLOBAL CROSSING LOCAL SERVICES, INC. - MD |
12 |
| CAVALIER TELEPHONE MID-ATLANTIC, LLC - MD |
10 |
| STARPOWER COMMUNICATIONS, LLC - MD |
10 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC |
9 |
| CAVALIER EAST, LLC - MD |
8 |
| COMCAST IP PHONE, LLC |
7 |
| ONVOY, LLC - MD |
6 |
| PAETEC COMMUNICATIONS, INC. - MD |
6 |
| PEERLESS NETWORK OF MARYLAND, LLC |
6 |
| TELEPORT COMMUNICATIONS AMERICA, LLC - DC |
5 |
| BANDWIDTH.COM CLEC, LLC - MD |
4 |
| CORE COMMUNICATIONS, INC.- MD |
4 |
| SPRINT SPECTRUM, LP - MD |
4 |
| ATX COMMUNICATIONS SERVICES, LTD. |
2 |
| LIGHTWAVE COMMUNICATIONS, LLC - MD |
2 |
| LOCAL ACCESS LLC - MD |
2 |
| NUSO, LLC |
2 |
| YMAX COMMUNICATIONS CORP. - MD |
2 |
| AT&T - LOCAL |
1 |
| BALTIMORE-WASHINGTON TELEPHONE (BWT) |
1 |
| LEVEL 3 TELECOM OF MARYLAND, LLC - MD |
1 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD |
1 |
| METROPCS, INC. |
1 |
| PAETEC COMMUNICATIONS, INC. - DC |
1 |
| TELEPORT COMMUNICATIONS AMERICA, LLC - MD |
1 |
Prefixes by Rate Center
| Rate Center |
Number of Prefixes |
| WSHNGTNZN3 |
56 |
| WSHNGTNZN2 |
45 |
| WSNGTNZN10 |
36 |
| GAITHERSBG |
30 |
| FREDERICK |
25 |
| WALDORF |
18 |
| LAUREL236 |
17 |
| WSHNGTNZN4 |
14 |
| HAGERSTOWN |
13 |
| WSHNGTNZN5 |
12 |
| ASHTON236 |
10 |
| WSNGTNZN11 |
10 |
| LEONARDTN |
9 |
| WSNG236Z13 |
9 |
| WSNG236Z14 |
8 |
| CUMBERLAND |
7 |
| LAUREL238 |
6 |
| LXTNPKGRML |
5 |
| WSNGTNZN12 |
5 |
| WSHNGTNZN6 |
4 |
| ASHTON238 |
3 |
| BUCKEYSTN |
3 |
| DAMASCS236 |
3 |
| INDIANHEAD |
3 |
| MYERSVILLE |
3 |
| MECHANCSVL |
2 |
| NANJEMOY |
2 |
| WSNG236Z15 |
2 |
| WSNGTNZN16 |
2 |
| HUGHESVL |
1 |
| LA PLATA |
1 |
| MIDDLETOWN |
1 |
| MOUNT AIRY |
1 |
| OAKLAND |
1 |
| RIDGE |
1 |
| WILLIAMSPT |
1 |
| WSNG238Z13 |
1 |
| WSNG238Z14 |
1 |
Other Maryland Area Codes
Lookup phone numbers starting with other Maryland area codes:
Maryland Reverse Lookup ➜