Area Code 603-429 located in MERRIMACK, HILLSBOROUGH, NH, more detail is as below. Place NPA (Numbering Plan Area) : 603 NXX (Local Number Prefix) : 429 City : MERRIMACK 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 : MERRIMACK ZIP Code Count : 2374 ZIP Code Frequency : 82 ZIP Code : 03054 Other Information NPANXX : 603429 County Population : 0 Switch CLLI (Common Language Location Identifier) : MRMCNHYADS1 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 : NO NEW ENGLAND TEL OP DBA FAIRPOINT COMM - NH OCN (Operating Company Number) : 5113 Coverage Area Name : MERRIMACK Latitude : 42.8589 Longitude : -71.4907 ‹ previous : 603-429 next › : 603-430 Telephone Number List 603-429-0000 ~ 603-429-9999