Area Code 203-777 located in NEW HAVEN, NEW HAVEN, CT, more detail is as below. Place NPA (Numbering Plan Area) : 203 NXX (Local Number Prefix) : 777 City : NEW HAVEN County : NEW HAVEN State : CT (Connecticut) NXX Use Type : Landline NXX Intro Version : 1994-02-04 FIPS (Federal Information Processing Standards) : 09009 LATA (Local Access Transport Area) : 920 Rate Center : NEW HAVEN ZIP Code Count : 337 ZIP Code Frequency : 10 ZIP Code : 06510 Other Information NPANXX : 203777 County Population : 0 Switch CLLI (Common Language Location Identifier) : NWHNCT03CG1 MSA CBSA (Core Based Statistical Area) : New Haven-Milford, CT MSA CBSA Code (Core Based Statistical Area) : 35300 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : SOUTHERN NEW ENGLAND TELEPHONE CO. OCN (Operating Company Number) : 9147 Coverage Area Name : NEW HAVEN Latitude : 41.3042 Longitude : -72.9236 ‹ previous : 203-777 next › : 203-777 Telephone Number List 203-777-0000 ~ 203-777-9999