Area code 720 is an overlay for area code 303, covering the Denver metropolitan area and much of north-central Colorado. Introduced in 1998, 720 was implemented to ensure a sufficient supply of numbers in the fast-growing Front Range Urban Corridor. The 720/303 region includes cities like Denver, Aurora, Boulder, and Lakewood, serving as the state’s economic, political, and cultural hub. Known for its proximity to the Rocky Mountains, this area blends outdoor lifestyle with high-tech industry and a vibrant arts scene. Ten-digit dialing is required throughout the region. While 303 holds historical weight, 720 has become equally prominent, especially among newer businesses and residents.