203 Area Code
The 203 area code is serving the southwestern part of Connecticut, largely coextensive with the Connecticut portion of the New York metropolitan area.
Federal Data
State Data
County Data
City Data
The 203 area code is serving the southwestern part of Connecticut, largely coextensive with the Connecticut portion of the New York metropolitan area.
Federal Data
State Data
County Data
City Data
The 203 area code covers the southwestern portion of Connecticut, including most of Fairfield County, all of New Haven County, and a small portion of Litchfield County.
Area code 203 is overlaid by area code 475. Area code 203 was established in 1947. Area code 475 was added on December 12, 2009. All callers in Connecticut must dial all calls with ten digits.
Area code 203 is a general purpose code which was placed in service on January 1, 1947.
Our Connecticut phone number lookup service will analyze the three-digit prefix of any 203 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, Connecticut geographic region, and local calling area associated with the phone number.
Phone numbers follow the following structure under the North American Numbering Plan:
Understanding the area code can help you determine if a call is local to your area. However, keep in mind that due to mobile number portability and VoIP services, the caller may be anywhere in the United States, so it’s best to search for the most recent phone number details.
| Company | Number of Prefixes |
|---|---|
| SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT | 331 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT | 60 |
| NEW CINGULAR WIRELESS PCS, LLC - DC | 51 |
| SPRINT SPECTRUM, L.P. | 44 |
| CABLEVISION LIGHTPATH, INC. - CT | 36 |
| TELEPORT COMMUNICATIONS AMERICA, LLC - CT | 33 |
| LEVEL 3 COMMUNICATIONS, LLC - CT | 25 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT | 24 |
| OMNIPOINT COMMUNICATIONS, INC. - CT | 22 |
| GLOBAL CROSSING LOCAL SERVICES, INC. - CT | 20 |
| PAETEC COMMUNICATIONS, LLC - CT | 18 |
| CHOICE ONE COMMUNICATIONS, INC. - CT | 15 |
| VERIZON NEW YORK, INC. | 15 |
| AT&T - LOCAL | 14 |
| COMCAST IP PHONE, LLC | 7 |
| METROPCS, INC. | 5 |
| BANDWIDTH.COM CLEC, LLC - CT | 4 |
| CONVERSENT COMMUNICATIONS OF CONNECTICUT, LLC - CT | 4 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 4 |
| CTC COMMUNICATIONS CORP. - CT | 3 |
| TC SYSTEMS, INC. - NY | 2 |
| ONVOY, LLC - CT | 1 |
| PAETEC COMMUNICATIONS, INC. - NY | 1 |
| PEERLESS NETWORK OF CONNECTICUT, LLC - CT | 1 |
Carrier names have been updated from their original FCC assignments to reflect current companies following mergers, acquisitions, and rebranding. Updates were determined using AI-assisted research and may not be accurate or reflect up to date changes. This data is provided without warranties of accuracy or completeness.
| Rate Center | Number of Prefixes |
|---|---|
| NEW HAVEN | 135 |
| STAMFORD | 93 |
| BRIDGEPORT | 91 |
| NORWALK | 54 |
| DANBURY | 53 |
| WATERBURY | 52 |
| GREENWICH | 26 |
| MERIDEN | 24 |
| ANSONIDRBY | 17 |
| WESTPORT | 16 |
| MILFORD | 14 |
| WALLINGFD | 14 |
| DARIEN | 13 |
| FAIRFIELD | 13 |
| HUNTINGTON | 13 |
| TRUMBULL | 13 |
| BRANFORD | 10 |
| CHESHIRE | 9 |
| NEW CANAAN | 8 |
| WILTON | 8 |
| WOODBURY | 8 |
| BYRAM | 7 |
| GUILFORD | 7 |
| MADISON | 6 |
| NAUGATUCK | 6 |
| NEWTOWN | 5 |
| OLDGRNWICH | 5 |
| RIDGEFIELD | 5 |
| SEYMOUR | 4 |
| WOLCOTT | 4 |
| GEORGETOWN | 3 |
| REDDING | 3 |
| XXXXXXXXXX | 1 |
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