What area code is Boulder, CO?
| City | Boulder, CO |
|---|---|
| State | Colorado |
| Area codes | 303 and 720 |
| Time zone | Mountain Time |
| Phone prefixes | 18 in our data |
Look up a Boulder number
Boulder’s area codes
| Area code | Also covers |
|---|---|
| 303 | Denver, Aurora, Littleton and Longmont |
| 720 | Denver, Longmont, Fort Lupton and Georgetown |
Other places in area code 303
- Denver, CO
- Aurora, CO
- Littleton, CO
- Longmont, CO
- Fort Lupton, CO
- Golden, CO
- Broomfield, CO
- Englewood, CO
- Lakewood, CO
- Brighton, CO
- Highlands Ranch, CO
- Castle Rock, CO
- Evergreen, CO
- Keenesburg, CO
- Parker, CO
- Georgetown, CO
- Hudson, CO
- Lyons, CO
- Bennett, CO
- Byers, CO
- Strasburg, CO
Questions
- What is the area code for Boulder, Colorado?
- Boulder uses 2 area codes: 303 and 720. 303 is the original or most common one, and newer numbers can be given 720.
- What time zone is Boulder in?
- Boulder is in Mountain Time.
- Do I need to dial the area code for a local call in Boulder?
- Yes. Because Boulder has more than one area code, local calls need all 10 digits: the area code plus the 7-digit number.
- How do I call Boulder from another country?
- Dial your country’s exit code (011 from most places, 00 from Europe), then 1, then the area code and number: +1 303 XXX XXXX.