| District of Colorado area codes: 720 | |
|---|---|
| Country | United States |
| State/Province | Colorado |
| Major City | Denver |
| Time Zone | Mountain |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 720-200 | Denver | Denver, CO | Qwest Corporation |
| 720-201 | Denver | Denver, CO | New Cingular Wireless PCS |
| 720-202 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 720-203 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 720-204 | Boulder | Longmont, CO | AT&T Local |
| 720-205 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 720-206 | Jefferson | Denver, CO | Xo Colorado |
| 720-207 | Arapahoe | Englewood, CO | Xo Colorado |
| 720-208 | Jefferson | Denver, CO | Xo Colorado |
| 720-209 | Denver | Denver, CO | Sprint Spectrum L.p. |
| 720-210 | Jefferson | Denver, CO | Xo Colorado |
| 720-212 | Jefferson | Denver, CO | Xo Colorado |
| 720-213 | Denver | Denver, CO | Mcleodusa Telecommunications Services- Co |
| 720-214 | Denver | Denver, CO | Mcleodusa Telecommunications Services- Co |
| 720-215 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 720-216 | Arapahoe | Aurora, CO | Teleport Communications America |
| 720-217 | Jefferson | Denver, CO | T-mobile Usa |
| 720-218 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 720-219 | Jefferson | Denver, CO | Cellco Partnership DBA Verizon Wireless |
| 720-220 | Jefferson | Denver, CO | T-mobile Usa |
There are 519 prefixes, In the code area, the major cities are Arvada, CO;Aurora, CO;Boulder, CO;Brighton, CO;Bro. The major city is Denver.