Colorado Area Codes: 720, 970, 303, 719, 983 – History & Regions
Colorado’s phone area codes reflect the state’s growth, population shifts, and technological evolution. From the historic 303 to the newest overlay 983, each code tells a story about a specific region of the state. This guide breaks down each area code, its history, coverage, and major cities.
📞 303 – The Original Colorado Area Code
Established: 1947
Type: Original area code
Coverage: Central Colorado including the Denver Metro
The 303 area code was part of the original AT&T and Bell Labs system implemented in 1947. Initially covering the entire state, it was gradually narrowed to cover central Colorado due to demand.
Major Cities: Denver, Boulder, Aurora, Lakewood, Arvada, Littleton, Centennial, Westminster
📞 720 – The First Overlay
Established: 1998
Type: Overlay for 303
Coverage: Denver Metro
Introduced due to the high demand in the 303 region, 720 became Colorado’s first overlay. It ushered in the requirement for 10-digit dialing across the metro area.
Major Cities: Denver, Aurora, Thornton, Parker, Englewood, Highlands Ranch
📞 970 – Western and Northern Colorado
Established: 1995
Type: Geographic split from 303
Coverage: Western and Northern Colorado
970 covers many of Colorado’s most scenic and rural regions. It was split off from 303 to support growth in mountain towns and the northern plains.
Major Cities: Fort Collins, Grand Junction, Durango, Greeley, Loveland, Vail, Aspen, Estes Park, Montrose
📞 719 – Southern and Southeastern Colorado
Established: 1988
Type: Geographic split from 303
Coverage: Southern and Southeastern Colorado
Created in 1988, the 719 area code serves Colorado Springs and other southern cities. It supports a significant military presence including Fort Carson and Peterson Space Force Base.
Major Cities: Colorado Springs, Pueblo, Cañon City, Alamosa, Trinidad, La Junta, Salida
📞 983 – The Newest Overlay
Established: 2022
Type: Overlay for 303/720
Coverage: Denver Metro
983 was activated in June 2022 to provide additional number availability in the densely populated Denver region. It is managed by the Colorado Public Utilities Commission.
Major Cities: Denver, Aurora, Boulder, Lakewood, Westminster
📍 Summary Table of Colorado Area Codes
| Area Code | Year Introduced | Type | Primary Regions Covered | Major Cities |
|---|---|---|---|---|
| 303 | 1947 | Original | Central Colorado | Denver, Boulder, Aurora |
| 720 | 1998 | Overlay | Denver Metro | Lakewood, Thornton, Parker |
| 970 | 1995 | Geographic | Northern and Western Colorado | Fort Collins, Grand Junction, Vail |
| 719 | 1988 | Geographic | Southern Colorado | Colorado Springs, Pueblo |
| 983 | 2022 | Overlay | Denver Metro | Denver, Boulder, Aurora |
📲 Why So Many Area Codes?
Colorado’s population has more than doubled since 1980. With more residents, businesses, and mobile devices, the need for unique phone numbers soared. Overlays like 720 and 983 allow for expansion without changing existing numbers. Learn more from NANPA.
❓ Frequently Asked Questions
Why does Colorado have multiple area codes?
As the population and demand for phone numbers grew—due to cell phones, internet-based calling, and business lines—Colorado needed new area codes to handle the volume. Some were geographic splits (like 719 and 970), while others were overlays (like 720 and 983).
Do I have to dial 10 digits for local calls in Colorado?
Yes. Because of overlays in the 303, 720, and 983 regions, 10-digit dialing is mandatory—even for local calls. This ensures accurate routing within areas that share the same number space.
Which area code is the most common in Denver?
The Denver metro area is served by three area codes: 303 (original), 720 (overlay since 1998), and 983 (newest overlay since 2022). All three are actively issued in the region.
Who assigns and manages Colorado’s area codes?
Area codes are managed by the North American Numbering Plan Administrator (NANPA), with oversight from the Colorado Public Utilities Commission.
Can I choose which area code I get?
Typically, no. New phone numbers are assigned based on availability in your region. If you’re in the Denver metro area, you might receive a 303, 720, or 983 number depending on current allocations.
