Area Code 603-478 located in ANTRIM, HILLSBOROUGH, NH, more detail is as below. Place NPA (Numbering Plan Area) : 603 NXX (Local Number Prefix) : 478 City : ANTRIM County : HILLSBOROUGH State : NH (New Hampshire) NXX Use Type : Landline NXX Intro Version : 1994-02-04 FIPS (Federal Information Processing Standards) : 33011 LATA (Local Access Transport Area) : 122 Rate Center : HLLSBUPVLG ZIP Code Count : 25 ZIP Code Frequency : 4 ZIP Code : 03440 Other Information NPANXX : 603478 County Population : 0 Switch CLLI (Common Language Location Identifier) : HUVGNHXADS0 MSA CBSA (Core Based Statistical Area) : Manchester-Nashua, NH MSA CBSA Code (Core Based Statistical Area) : 31700 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : GRANITE STATE TELEPHONE, INC. OCN (Operating Company Number) : 0039 Coverage Area Name : HILLSBORO Latitude : 43.1304 Longitude : -71.9764 ‹ previous : 603-478 next › : 603-478 Telephone Number List 603-478-0000 ~ 603-478-9999