Area Code 603-612 located in PLAISTOW, ROCKINGHAM, NH, more detail is as below. Place NPA (Numbering Plan Area) : 603 NXX (Local Number Prefix) : 612 City : PLAISTOW County : ROCKINGHAM State : NH (New Hampshire) NXX Use Type : Landline NXX Intro Version : 1999-10-13 FIPS (Federal Information Processing Standards) : 33015 LATA (Local Access Transport Area) : 122 Rate Center : PLAISTOW ZIP Code Count : 0 ZIP Code Frequency : Most frequently occurring ZIP Code, although percentage is unknown. ZIP Code : 03865 Other Information NPANXX : 603612 County Population : 0 Switch CLLI (Common Language Location Identifier) : NASHNH08DS0 MSA CBSA (Core Based Statistical Area) : Boston-Cambridge-Quincy, MA-NH MSA CBSA Code (Core Based Statistical Area) : 14460 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : CONVERSENT COMMUNICATIONS OF NEW HAMPSHIRE, LLC OCN (Operating Company Number) : 4053 Coverage Area Name : PLAISTOW Latitude : 42.8278 Longitude : -71.0916 ‹ previous : 603-610 next › : 603-613 Telephone Number List 603-612-0000 ~ 603-612-9999