303 Area Code: Cities, Time Zone and Zip Codes
What area code is 303? The area code 303 is located in Colorado and it serves Denver, Aurora, Lakewood, Thornton, Arvada, Westminster, Centennial, Boulder, Highlands Ranch, Longmont, and some other surrounding cities. The area code 303 was created on January 1, 1947 and was first put to use on January 1, 1947.
The top counties that are being served by the 303 area code are Adams County, Arapahoe County, Boulder County, Broomfield County, Clear Creek County, Denver County, Douglas County, Elbert County, Gilpin County, Jefferson County, Park County, and Weld County.
The major cities under each of these counties that are being served by the 303 area code are listed below:
Adams County
The cities within Adams County that are served by the 303 area code include Aurora, Bennett, Brighton, Byers, Commerce City, Denver, Dupont, Eastlake, Henderson, Strasburg, Thornton, and Westminster.
Arapahoe County
The cities within Arapahoe County that are served by the 303 area code include Aurora, Deer Trail, Englewood, Littleton, and Watkins.
Boulder County
The cities within Boulder County that are served by the 303 area code include Allenspark, Boulder, Eldorado Springs, Hygiene, Jamestown, Lafayette, Longmont, Louisville, Lyons, Nederland, Niwot, Pinecliffe, and Ward.
Broomfield County
The cities within Broomfield County that are served by the 303 area code include Broomfield.
Clear Creek County
The cities within Clear Creek County that are served by the 303 area code include Dumont, Empire, Georgetown, Idaho Springs, and Silver Plume.
Denver County
The cities within Denver County that are served by the 303 area code include Denver.
Douglas County
The cities within Douglas County that are served by the 303 area code include Castle Rock, Franktown, Larkspur, Littleton, Lone Tree, Louviers, Parker, and Sedalia.
Elbert County
The cities within Elbert County that are served by the 303 area code include Elbert, Elizabeth, and Kiowa.
Gilpin County
The cities within Gilpin County that are served by the 303 area code include Black Hawk, Central City, Golden, and Rollinsville.
Jefferson County
The cities within Jefferson County that are served by the 303 area code include Arvada, Broomfield, Buffalo Creek, Conifer, Denver, Evergreen, Golden, Idledale, Indian Hills, Kittredge, Littleton, Morrison, Pine, and Wheat Ridge.
Park County
The cities within Park County that are served by the 303 area code include Bailey, Grant, and Shawnee.
Weld County
The cities within Weld County that are served by the 303 area code include Dacono, Erie, Firestone, Fort Lupton, Frederick, Hudson, Keenesburg, Longmont, and Roggen.
303 Area Code Time Zone
What time zone is 303 Area Code? The time zone in the 303 area code is the Mountain Standard Time zone which is abbreviated as MST. The Mountain Standard Time is UTC/GMT -7:00 hours. The Daylight Saving Time (MDT) is +1.00 hour.
Significance of 303 Area Code
I don’t know if you notice that there is a three-digit number that precedes a telephone number any time you receive a call from your cell phone. Any time you see the three-digit code 303, it suggests that the call comes from any of the cities or counties listed above. However, there may be an exemption to this. With the use of mobile phone or roaming phone feature, the caller may not necessarily be at any of these cities or counties at the time of calling.
Nevertheless, knowing the counties and cities that the 303 area code covers can guide you when to call a particular person. This is because the person you want to call may be in a time zone that is different from your own.
Telephone Carriers in 303 Area Code
If you want to get a wireless telephone within the 303 area code, the popular wireless telephone carriers that you can approach include Cingular Wireless, Verizon Wireless, Sprint, T-mobile, American Messaging (am), Contact Paging, USA Mobility Wireless, N.E. Colorado Cellular, Elbert County Wireless, Big River TelephoneCo, Elbert County Wireless, and Comms Unlimited.
For landline, popular carriers are Qwest Corporation, Icg Telecom Group, Teleport America, MCI Metro ATS, Level 3 Comms, Global Crossing Local Services, Comcast Phone, AT&T Local, Convergence Comms, Xo Colorado, 360networks (USA), Cbeyond Comms, Mcleodusa Telecom Services, Live Wire Networks, Eschelon Telecom, 4division, Strasburg, Eastern Slope Rural Telephone Association, Ymax Comms Corp, Bijou Telephone Cooperative Association, Neutral tandem, Pac – West Telecomm, Newcloud Networks, Roggen Telephone Cooperative Co, and Forethought.net.
Zip Codes in 303 Area Code
| City | County | State | Area Code | Zip Code |
| Allenspark | Boulder | Colorado | 303 | 80510 |
| Arvada | Jefferson | Colorado | 303 | 80004 |
| Arvada | Jefferson | Colorado | 303 | 80005 |
| Arvada | Jefferson | Colorado | 303 | 80002 |
| Arvada | Jefferson | Colorado | 303 | 80003 |
| Arvada | Jefferson | Colorado | 303 | 80007 |
| Arvada | Jefferson | Colorado | 303 | 80001 |
| Arvada | Jefferson | Colorado | 303 | 80006 |
| Aurora | Arapahoe | Colorado | 303 | 80015 |
| Aurora | Arapahoe | Colorado | 303 | 80011 |
| Aurora | Arapahoe | Colorado | 303 | 80012 |
| Aurora | Arapahoe | Colorado | 303 | 80017 |
| Aurora | Arapahoe | Colorado | 303 | 80018 |
| Aurora | Adams | Colorado | 303 | 80019 |
| Aurora | Adams | Colorado | 303 | 80045 |
| Aurora | Arapahoe | Colorado | 303 | 80016 |
| Aurora | Arapahoe | Colorado | 303 | 80010 |
| Aurora | Arapahoe | Colorado | 303 | 80013 |
| Aurora | Arapahoe | Colorado | 303 | 80014 |
| Aurora | Arapahoe | Colorado | 303 | 80044 |
| Aurora | Adams | Colorado | 303 | 80040 |
| Aurora | Arapahoe | Colorado | 303 | 80042 |
| Aurora | Adams | Colorado | 303 | 80047 |
| Aurora | Adams | Colorado | 303 | 80041 |
| Aurora | Arapahoe | Colorado | 303 | 80046 |
| Bailey | Park | Colorado | 303 | 80421 |
| Bennett | Adams | Colorado | 303 | 80102 |
| Black Hawk | Gilpin | Colorado | 303 | 80422 |
| Boulder | Boulder | Colorado | 303 | 80301 |
| Boulder | Boulder | Colorado | 303 | 80303 |
| Boulder | Boulder | Colorado | 303 | 80304 |
| Boulder | Boulder | Colorado | 303 | 80305 |
| Boulder | Boulder | Colorado | 303 | 80309 |
| Boulder | Boulder | Colorado | 303 | 80302 |
| Boulder | Boulder | Colorado | 303 | 80307 |
| Boulder | Boulder | Colorado | 303 | 80310 |
| Boulder | Boulder | Colorado | 303 | 80314 |
| Boulder | Boulder | Colorado | 303 | 80308 |
| Boulder | Boulder | Colorado | 303 | 80306 |
| Brighton | Adams | Colorado | 303 | 80601 |
| Brighton | Adams | Colorado | 303 | 80602 |
| Brighton | Adams | Colorado | 303 | 80603 |
| Broomfield | Broomfield | Colorado | 303 | 80020 |
| Broomfield | Jefferson | Colorado | 303 | 80021 |
| Broomfield | Broomfield | Colorado | 303 | 80023 |
| Broomfield | Broomfield | Colorado | 303 | 80038 |
| Buffalo Creek | Jefferson | Colorado | 303 | 80425 |
| Byers | Adams | Colorado | 303 | 80103 |
| Castle Rock | Douglas | Colorado | 303 | 80104 |
| Castle Rock | Douglas | Colorado | 303 | 80108 |
| Castle Rock | Douglas | Colorado | 303 | 80109 |
| Central City | Gilpin | Colorado | 303 | 80427 |
| Commerce City | Adams | Colorado | 303 | 80022 |
| Commerce City | Adams | Colorado | 303 | 80037 |
| Conifer | Jefferson | Colorado | 303 | 80433 |
| Dacono | Weld | Colorado | 303 | 80514 |
| Deer Trail | Arapahoe | Colorado | 303 | 80105 |
| Denver | Denver | Colorado | 303 | 80216 |
| Denver | Denver | Colorado | 303 | 80220 |
| Denver | Denver | Colorado | 303 | 80224 |
| Denver | Jefferson | Colorado | 303 | 80225 |
| Denver | Denver | Colorado | 303 | 80203 |
| Denver | Denver | Colorado | 303 | 80205 |
| Denver | Denver | Colorado | 303 | 80206 |
| Denver | Denver | Colorado | 303 | 80207 |
| Denver | Denver | Colorado | 303 | 80209 |
| Denver | Denver | Colorado | 303 | 80210 |
| Denver | Denver | Colorado | 303 | 80211 |
| Denver | Denver | Colorado | 303 | 80212 |
| Denver | Jefferson | Colorado | 303 | 80215 |
| Denver | Denver | Colorado | 303 | 80218 |
| Denver | Adams | Colorado | 303 | 80221 |
| Denver | Jefferson | Colorado | 303 | 80226 |
| Denver | Jefferson | Colorado | 303 | 80228 |
| Denver | Denver | Colorado | 303 | 80230 |
| Denver | Denver | Colorado | 303 | 80231 |
| Denver | Jefferson | Colorado | 303 | 80232 |
| Denver | Adams | Colorado | 303 | 80233 |
| Denver | Adams | Colorado | 303 | 80234 |
| Denver | Jefferson | Colorado | 303 | 80235 |
| Denver | Denver | Colorado | 303 | 80236 |
| Denver | Denver | Colorado | 303 | 80237 |
| Denver | Denver | Colorado | 303 | 80239 |
| Denver | Denver | Colorado | 303 | 80247 |
| Denver | Adams | Colorado | 303 | 80260 |
| Denver | Denver | Colorado | 303 | 80262 |
| Denver | Denver | Colorado | 303 | 80246 |
| Denver | Denver | Colorado | 303 | 80202 |
| Denver | Adams | Colorado | 303 | 80229 |
| Denver | Denver | Colorado | 303 | 80249 |
| Denver | Jefferson | Colorado | 303 | 80214 |
| Denver | Denver | Colorado | 303 | 80223 |
| Denver | Jefferson | Colorado | 303 | 80227 |
| Denver | Denver | Colorado | 303 | 80238 |
| Denver | Denver | Colorado | 303 | 80204 |
| Denver | Denver | Colorado | 303 | 80208 |
| Denver | Denver | Colorado | 303 | 80219 |
| Denver | Denver | Colorado | 303 | 80222 |
| Denver | Denver | Colorado | 303 | 80295 |
| Denver | Denver | Colorado | 303 | 80291 |
| Denver | Denver | Colorado | 303 | 80259 |
| Denver | Denver | Colorado | 303 | 80265 |
| Denver | Denver | Colorado | 303 | 80251 |
| Denver | Denver | Colorado | 303 | 80299 |
| Denver | Denver | Colorado | 303 | 80271 |
| Denver | Denver | Colorado | 303 | 80266 |
| Denver | Denver | Colorado | 303 | 80263 |
| Denver | Denver | Colorado | 303 | 80250 |
| Denver | Denver | Colorado | 303 | 80273 |
| Denver | Denver | Colorado | 303 | 80294 |
| Denver | Denver | Colorado | 303 | 80264 |
| Denver | Denver | Colorado | 303 | 80217 |
| Denver | Denver | Colorado | 303 | 80248 |
| Denver | Denver | Colorado | 303 | 80256 |
| Denver | Denver | Colorado | 303 | 80281 |
| Denver | Denver | Colorado | 303 | 80244 |
| Denver | Denver | Colorado | 303 | 80201 |
| Denver | Denver | Colorado | 303 | 80243 |
| Denver | Denver | Colorado | 303 | 80290 |
| Denver | Denver | Colorado | 303 | 80252 |
| Denver | Denver | Colorado | 303 | 80293 |
| Denver | Denver | Colorado | 303 | 80257 |
| Denver | Denver | Colorado | 303 | 80261 |
| Denver | Denver | Colorado | 303 | 80274 |
| Dumont | Clear Creek | Colorado | 303 | 80436 |
| Dupont | Adams | Colorado | 303 | 80024 |
| Eastlake | Adams | Colorado | 303 | 80614 |
| Elbert | Elbert | Colorado | 303 | 80106 |
| Eldorado Springs | Boulder | Colorado | 303 | 80025 |
| Elizabeth | Elbert | Colorado | 303 | 80107 |
| Empire | Clear Creek | Colorado | 303 | 80438 |
| Englewood | Arapahoe | Colorado | 303 | 80111 |
| Englewood | Arapahoe | Colorado | 303 | 80112 |
| Englewood | Arapahoe | Colorado | 303 | 80113 |
| Englewood | Arapahoe | Colorado | 303 | 80110 |
| Englewood | Arapahoe | Colorado | 303 | 80155 |
| Englewood | Arapahoe | Colorado | 303 | 80150 |
| Englewood | Arapahoe | Colorado | 303 | 80151 |
| Erie | Weld | Colorado | 303 | 80516 |
| Evergreen | Jefferson | Colorado | 303 | 80439 |
| Evergreen | Jefferson | Colorado | 303 | 80437 |
| Firestone | Weld | Colorado | 303 | 80520 |
| Fort Lupton | Weld | Colorado | 303 | 80621 |
| Franktown | Douglas | Colorado | 303 | 80116 |
| Frederick | Weld | Colorado | 303 | 80530 |
| Georgetown | Clear Creek | Colorado | 303 | 80444 |
| Golden | Jefferson | Colorado | 303 | 80401 |
| Golden | Gilpin | Colorado | 303 | 80403 |
| Golden | Jefferson | Colorado | 303 | 80402 |
| Golden | Jefferson | Colorado | 303 | 80419 |
| Grant | Park | Colorado | 303 | 80448 |
| Henderson | Adams | Colorado | 303 | 80640 |
| Hudson | Weld | Colorado | 303 | 80642 |
| Hygiene | Boulder | Colorado | 303 | 80533 |
| Idaho Springs | Clear Creek | Colorado | 303 | 80452 |
| Idledale | Jefferson | Colorado | 303 | 80453 |
| Indian Hills | Jefferson | Colorado | 303 | 80454 |
| Jamestown | Boulder | Colorado | 303 | 80455 |
| Keenesburg | Weld | Colorado | 303 | 80643 |
| Kiowa | Elbert | Colorado | 303 | 80117 |
| Kittredge | Jefferson | Colorado | 303 | 80457 |
| Lafayette | Boulder | Colorado | 303 | 80026 |
| Larkspur | Douglas | Colorado | 303 | 80118 |
| Littleton | Arapahoe | Colorado | 303 | 80121 |
| Littleton | Arapahoe | Colorado | 303 | 80122 |
| Littleton | Jefferson | Colorado | 303 | 80123 |
| Littleton | Douglas | Colorado | 303 | 80125 |
| Littleton | Douglas | Colorado | 303 | 80126 |
| Littleton | Jefferson | Colorado | 303 | 80128 |
| Littleton | Douglas | Colorado | 303 | 80130 |
| Littleton | Douglas | Colorado | 303 | 80129 |
| Littleton | Arapahoe | Colorado | 303 | 80120 |
| Littleton | Jefferson | Colorado | 303 | 80127 |
| Littleton | Jefferson | Colorado | 303 | 80162 |
| Littleton | Arapahoe | Colorado | 303 | 80161 |
| Littleton | Douglas | Colorado | 303 | 80163 |
| Littleton | Arapahoe | Colorado | 303 | 80165 |
| Littleton | Arapahoe | Colorado | 303 | 80166 |
| Littleton | Arapahoe | Colorado | 303 | 80160 |
| Lone Tree | Douglas | Colorado | 303 | 80124 |
| Longmont | Boulder | Colorado | 303 | 80503 |
| Longmont | Weld | Colorado | 303 | 80504 |
| Longmont | Boulder | Colorado | 303 | 80501 |
| Longmont | Boulder | Colorado | 303 | 80502 |
| Louisville | Boulder | Colorado | 303 | 80027 |
| Louviers | Douglas | Colorado | 303 | 80131 |
| Lyons | Boulder | Colorado | 303 | 80540 |
| Morrison | Jefferson | Colorado | 303 | 80465 |
| Nederland | Boulder | Colorado | 303 | 80466 |
| Niwot | Boulder | Colorado | 303 | 80544 |
| Parker | Douglas | Colorado | 303 | 80134 |
| Parker | Douglas | Colorado | 303 | 80138 |
| Pine | Jefferson | Colorado | 303 | 80470 |
| Pinecliffe | Boulder | Colorado | 303 | 80471 |
| Roggen | Weld | Colorado | 303 | 80652 |
| Rollinsville | Gilpin | Colorado | 303 | 80474 |
| Sedalia | Douglas | Colorado | 303 | 80135 |
| Shawnee | Park | Colorado | 303 | 80475 |
| Silver Plume | Clear Creek | Colorado | 303 | 80476 |
| Strasburg | Adams | Colorado | 303 | 80136 |
| Thornton | Adams | Colorado | 303 | 80241 |
| Ward | Boulder | Colorado | 303 | 80481 |
| Watkins | Arapahoe | Colorado | 303 | 80137 |
| Westminster | Adams | Colorado | 303 | 80030 |
| Westminster | Adams | Colorado | 303 | 80031 |
| Westminster | Adams | Colorado | 303 | 80035 |
| Westminster | Adams | Colorado | 303 | 80036 |
| Wheat Ridge | Jefferson | Colorado | 303 | 80033 |
| Wheat Ridge | Jefferson | Colorado | 303 | 80034 |