interlink adv svc dba forethought.net - co . View all zip codes in CO or use the free zip code lookup. It has the following active area codes: 303. Area Code Map of Colorado The US country code and Colorado US area code chart below gives you the necessary information for calling American cities. Standard Arvada Jefferson County Area Code 303 Area Code 720. Denver, CO is officially utilizing an area code overlay in which area codes 303 and 720 serve the same geographic area. Ten digit dialing (area code + seven digit number) is necessary. PO Box Arvada Jefferson County Area Code 303. Get a local Colorado number for your business. Denver Area Code: 303. The state of Colorado is served by the following area codes: . 80002. 303-816 United States Phone Code: 1. 80003. The International dialing code calculator will show how to dial to USA â Colorado â Denver from any location in the world, with local area codes, trunk prefixes and international country codes 2021 Denver area code information: Area codes for Denver and Colorado; Area codes by town 2/3/05. All United States phone numbers are 10-digits total, including a 3-digit area code and a 7-digit local subscriber number. On November 10, 1951, the first long distance, direct call was made by Englewood Mayor M. Leslie Denning to Frank Osborn, the mayor of Alameda, California. 303/720 â which serve Denver and Boulder 719-which serves Colorado Springs and southeastern Colorado970- which serves northern and western Colorado History of Colorado Area Codes: 01/01/1947 Area code 303 was out into service. 720. 1995 area code 303 was break to form area code 970. Share: ... Area Codes 80001. In 1988 Area code 303 was break to form area code 719. In addition to Denver, CO area code information read more about area codes 303 and 720 details and Colorado area codes.. Denver, CO is located in Denver County and observes the Mountain Time Zone. View our Colorado area code information. Colorado States Is Served By These Area Code. Area codes were given as routing codes to operators in 1947. 303/720, which serve Denver and Boulder; 719, which serves Colorado Springs and southeastern Colorado; 970, which serves northern and western Colorado Area Codes > Colorado > Denver; The city of Denver is in the state of Colorado. In Denver, area codes are always included in written telephone numbers and area codes must be dialed for all calls, even for local calling. For international dialing codes and detailed dialing instructions to Colorado United States, use our drop down boxes at the top of this page or check out our easy-to-use country code search tool . Area Code Prefix Usage Primary City Carrier Introduced; 303 (303) 200- Landline : Denver Teleport Communications America : 01/25/1998 : 303 (303) 201- Wireless Denver Dial Code: +1 303 Colorado ZIP code map and Colorado ZIP code list. Grasshopper can provide you a Colorado phone number including 303, 719, 720, and 970 area codes. Lookup area codes by state.