Area Code 231-923 located in HART, OCEANA, MI, more detail is as below. Place NPA (Numbering Plan Area) : 231 NXX (Local Number Prefix) : 923 City : HART County : OCEANA State : MI (Michigan) NXX Use Type : Landline NXX Intro Version : 2001-10-31 FIPS (Federal Information Processing Standards) : 26127 LATA (Local Access Transport Area) : 348 Rate Center : HART ZIP Code Count : 0 ZIP Code Frequency : Most frequently occurring ZIP Code, although percentage is unknown. ZIP Code : 49420 Other Information NPANXX : 231923 County Population : 0 Switch CLLI (Common Language Location Identifier) : GDRPMIBLXGX Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : SPRINT SPECTRUM L.P. OCN (Operating Company Number) : 6664 Coverage Area Name : HART Latitude : 43.6999 Longitude : -86.3711 ‹ previous : 231-922 next › : 231-924 Telephone Number List 231-923-0000 ~ 231-923-9999