what area code is 303

The 303 area code is located in central Colorado and covers Denver, Aurora, Lakewood, Thornton, Arvada, Westminster, and Centennial. It is one of the original 86 area codes created by AT&T and the Bell System in 1947 and originally served the entire state of Colorado. In 1995, area code 303 was split, creating the need to update some of the phone numbers to area code 970. In 1998, area code 720 was created and is currently an overlay to 303. In 2022, area code 983 was created and is also an overlay to 303.