Area Code 303-528 located in DENVER, DENVER, CO, more detail is as below. Place NPA (Numbering Plan Area) : 303 NXX (Local Number Prefix) : 528 City : DENVER County : DENVER State : CO (Colorado) NXX Use Type : Wireless NXX Intro Version : 1994-02-04 FIPS (Federal Information Processing Standards) : 08031 LATA (Local Access Transport Area) : 656 Rate Center : DENVER ZIP Code Count : 1 ZIP Code Frequency : 100 ZIP Code : 80237 Other Information NPANXX : 303528 County Population : 0 Switch CLLI (Common Language Location Identifier) : DNVRCOMHCM1 MSA CBSA (Core Based Statistical Area) : Denver-Aurora, CO MSA CBSA Code (Core Based Statistical Area) : 19740 Time Zone : Mountain (GMT -07:00) Observes Daylight Saving Time : Yes Company : AMERICAN MESSAGING (AM), INC. OCN (Operating Company Number) : 9748 Coverage Area Name : DENVER Latitude : 39.7454 Longitude : -105.0512 ‹ previous : 303-527 next › : 303-529 Telephone Number List 303-528-0000 ~ 303-528-9999