About Area Code 303
Area code 303 serves Colorado, covering major cities including Denver, Aurora. Operating in the Mountain Time (MT), this code was established in 1947.
| State | Time Zone | Cities |
|---|---|---|
| Colorado | Mountain Time (MT) | Denver, Aurora |
Active Area Code
303
Colorado
Mountain Time (MT)
Est. 1947
PRIMARY
Location
Colorado
Denver
ACTIVE
Coverage
2 Cities
Since 1947
Beware of Spam Calls
Scammers frequently use 303 numbers. Always verify unknown callers before sharing personal information.
Protect Yourself NowCommon Questions
Where is 303?
Located in Colorado, serving Denver and surrounding areas.
What time zone?
Operates in Mountain Time (MT).
When established?
Area code 303 was introduced in 1947.
Used for spam?
Can be used by legitimate and fraudulent callers. Always verify unknown numbers.