| District of Colorado area codes: 303 | |
|---|---|
| Country | United States |
| State/Province | Colorado |
| Major City | Denver |
| Time Zone | Mountain (UTC-07:00) |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 303-891 | Jefferson | Denver, CO | Usa Mobility Wireless |
| 303-892 | Denver | Denver, CO | Qwest Corporation |
| 303-893 | Denver | Denver, CO | Qwest Corporation |
| 303-894 | Denver | Denver, CO | Qwest Corporation |
| 303-895 | Denver | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-896 | Denver | Denver, CO | Qwest Corporation |
| 303-897 | Jefferson | Denver, CO | Usa Mobility Wireless |
| 303-898 | Jefferson | Denver, CO | New Cingular Wireless PCS |
| 303-899 | Denver | Denver, CO | Qwest Corporation |
| 303-900 | Clear Creek | Idaho Springs, CO | Level 3 Communications |
| 303-901 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 303-902 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-903 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-904 | Jefferson | Denver, CO | Qwest Corporation |
| 303-905 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-906 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-907 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-908 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-909 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 303-910 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
There are 783 prefixes, In the code area, the major cities are Arvada, CO;Aurora, CO;Boulder, CO;Brighton, CO;Bro. The major city is Denver.