303 area code
Area code 303 is in Colorado, United States, in the Mountain time zone. It covers Arvada, Aurora, Boulder, Brighton, Broomfield, Castle Rock and more.
State / Province
Colorado (CO)
Country
United States
Region
West
Time zone
Mountain
Current local time
—
Approx. location
39.7776, -105.0027 ↗
How to dial a 303 number
- National format
- (303) 555-0100
- International (E.164)
- +1 303 555 0100
- From abroad
- +1 303 …
Cities & areas in the 303 area code
24 known locations — a selection:
Arvada
Aurora
Boulder
Brighton
Broomfield
Castle Rock
Castlewood
Columbine
Commerce City
Denver
Englewood
Highlands Ranch
Ken Caryl
Lafayette
About area code 303
Area code 303 is one of the North American Numbering Plan (NANP) codes serving Colorado. In the NANP a full number looks like +1 (303) NXX-XXXX: the +1 is the country code for the US and Canada, 303 is the area code, and the remaining seven digits identify the specific line. A call is charged by your own carrier's plan, not by the area code itself.