Area Code 603-378 located in HAMPSTEAD, ROCKINGHAM, NH, more detail is as below. Place NPA (Numbering Plan Area) : 603 NXX (Local Number Prefix) : 378 City : HAMPSTEAD County : ROCKINGHAM State : NH (New Hampshire) NXX Use Type : Landline NXX Intro Version : 1997-04-01 FIPS (Federal Information Processing Standards) : 33015 LATA (Local Access Transport Area) : 122 Rate Center : PLAISTOW ZIP Code Count : 85 ZIP Code Frequency : 13 ZIP Code : 03841 Other Information NPANXX : 603378 County Population : 0 Switch CLLI (Common Language Location Identifier) : PLSTNHMADS0 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 : NO NEW ENGLAND TEL OP DBA FAIRPOINT COMM - NH OCN (Operating Company Number) : 5113 Coverage Area Name : PLAISTOW Latitude : 42.8278 Longitude : -71.0916 ‹ previous : 603-378 next › : 603-378 Telephone Number List 603-378-0000 ~ 603-378-9999