Colorado · Area code
Area Code 303Denver, CO
Area code 303 is in Colorado, United States, and serves Denver, Aurora, Boulder, Littleton and Golden and other places nearby. Its time zone is Mountain Time.
Area code 303 at a glance
- Area code
- 303
- Main place
- Denver, CO
- State
- Colorado
- Country
- 🇺🇸 United States
- Country calling code
- +1
- Time zone
- Mountain Time (America/Denver)
- Dial from abroad
- +1 303 XXX XXXX
- Dial inside the US and Canada
- 1 303 XXX XXXX
Cities and places in area code 303
The places phone numbers beginning 303 were issued in, the most common first.
- Denver, CO
- Aurora, CO
- Boulder, CO
- Littleton, CO
- Golden, CO
- Longmont, CO
- Broomfield, CO
- Lakewood, CO
- Englewood, CO
- Brighton, CO
- Highlands Ranch, CO
- Castle Rock, CO
- Evergreen, CO
- Parker, CO
- Arvada, CO
- Bennett, CO
- Black Hawk, CO
- Byers, CO
- Elbert, CO
- Elizabeth, CO
- Erie, CO
- Fort Lupton, CO
- Georgetown, CO
- Hudson, CO
- Idaho Springs, CO
- Keenesburg, CO
- Kiowa, CO
- Larkspur, CO
- Louisville, CO
- Lyons, CO
- Morrison, CO
- Nederland, CO
- Niwot, CO
- Strasburg, CO
Look up a 303 number
Enter a full number with area code 303: it shows the line type, place, network and time zone, and every way to write it. Free and private.
Area code 303: frequently asked questions
Where is area code 303?
Area code 303 is in Colorado, United States. It serves places including Denver, Aurora, Boulder, Littleton, Golden, Longmont, Broomfield and Lakewood.
What time zone is area code 303 in?
Area code 303 is on Mountain Time. A number with this area code can belong to someone living anywhere, so the time zone tells you where the number was issued rather than where the person is.
Which country is area code 303 in?
Area code 303 belongs to the United States, part of the North American Numbering Plan. Country code +1 is shared by the United States, Canada and many Caribbean and Pacific countries; the area code decides which one a number is in.
How do I call a 303 number from another country?
Dial your country's international access code (or press + on a mobile phone), then 1, then 303, then the seven-digit number: +1 303 followed by the number. Inside the United States and Canada, dial 1 and the ten digits.
Can I tell who is calling from an area code?
No. The area code only shows where a number was first issued. People keep their numbers when they move, mobile numbers work anywhere, and callers can disguise the number they call from. To see what the numbering plan says about a specific number, use the free phone number lookup.
What other area codes are in Colorado?
Other area codes in Colorado include 719, 720, 748, 970 and 983.