Area Code 203-458 located in GUILFORD, NEW HAVEN, CT, more detail is as below. Place NPA (Numbering Plan Area) : 203 NXX (Local Number Prefix) : 458 City : GUILFORD 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 : GUILFORD ZIP Code Count : 1809 ZIP Code Frequency : 100 ZIP Code : 06437 Other Information NPANXX : 203458 County Population : 0 Switch CLLI (Common Language Location Identifier) : GUFDCT00DS0 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 : GUILFORD Latitude : 41.2841 Longitude : -72.6821 ‹ previous : 203-457 next › : 203-459 Telephone Number List 203-458-0000 ~ 203-458-9999