Area Code 303-381 located in BOULDER, BOULDER, CO, more detail is as below. Place NPA (Numbering Plan Area) : 303 NXX (Local Number Prefix) : 381 City : BOULDER County : BOULDER State : CO (Colorado) NXX Use Type : Landline NXX Intro Version : 1997-04-01 FIPS (Federal Information Processing Standards) : 08013 LATA (Local Access Transport Area) : 656 Rate Center : DENVER ZIP Code Count : 3 ZIP Code Frequency : 33 ZIP Code : 80302 Other Information NPANXX : 303381 County Population : 0 Switch CLLI (Common Language Location Identifier) : DNVRCO26DS1 MSA CBSA (Core Based Statistical Area) : Boulder, CO MSA CBSA Code (Core Based Statistical Area) : 14500 Time Zone : Mountain (GMT -07:00) Observes Daylight Saving Time : Yes Company : ICG TELECOM GROUP - CO OCN (Operating Company Number) : 7801 Coverage Area Name : DENVER Latitude : 39.7467 Longitude : -104.9948 ‹ previous : 303-381 next › : 303-382 Telephone Number List 303-381-0000 ~ 303-381-9999