Area Code 289-231 located in NEWMARKET, , ON, more detail is as below. Place NPA (Numbering Plan Area) : 289 NXX (Local Number Prefix) : 231 City : NEWMARKET State : ON (Ontario) NXX Use Type : Wireless NXX Intro Version : 2001-10-31 LATA (Local Access Transport Area) : 851 ZIP Code Count : 0 ZIP Code Frequency : Most frequently occurring ZIP Code, although percentage is unknown. Other Information NPANXX : 289231 County Population : 45294 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Coverage Area Name : NEWMARKET Latitude : 44.0534 Longitude : -79.4598 ‹ previous : 289-228 next › : 289-235 Telephone Number List 289-231-0000 ~ 289-231-9999