Area Code 603-400 located in HOLLIS, HILLSBOROUGH, NH, more detail is as below. Place NPA (Numbering Plan Area) : 603 NXX (Local Number Prefix) : 400 City : HOLLIS County : HILLSBOROUGH State : NH (New Hampshire) NXX Use Type : Landline NXX Intro Version : 8/31/2011 FIPS (Federal Information Processing Standards) : 33011 LATA (Local Access Transport Area) : 122 Rate Center : HOLLIS ZIP Code Count : 0 ZIP Code Frequency : 0 ZIP Code : 03049 Other Information NPANXX : 603400 County Population : 0 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 : CHARTER FIBERLINK NH-CCO, LLC - NH OCN (Operating Company Number) : 497G Coverage Area Name : HOLLIS Latitude : 42.7352 Longitude : -71.5885 ‹ previous : 603-399 next › : 603-401 Telephone Number List 603-400-0000 ~ 603-400-9999