Area Code 203-638 located in MIDDLETOWN, MIDDLESEX, CT, more detail is as below. Place NPA (Numbering Plan Area) : 203 NXX (Local Number Prefix) : 638 City : MIDDLETOWN County : MIDDLESEX State : CT (Connecticut) NXX Use Type : Landline NXX Intro Version : 1999-10-13 FIPS (Federal Information Processing Standards) : 09007 LATA (Local Access Transport Area) : 920 Rate Center : TRUMBULL ZIP Code Count : 1 ZIP Code Frequency : 100 ZIP Code : 06457 Other Information NPANXX : 203638 County Population : 0 Switch CLLI (Common Language Location Identifier) : SMFRCTATW51 MSA CBSA (Core Based Statistical Area) : Hartford-West Hartford-East Hartford, CT MSA CBSA Code (Core Based Statistical Area) : 25540 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : PAETEC COMMUNICATIONS, INC. - CT OCN (Operating Company Number) : 3083 Coverage Area Name : TRUMBULL Latitude : 41.2626 Longitude : -73.2211 ‹ previous : 203-637 next › : 203-639 Telephone Number List 203-638-0000 ~ 203-638-9999