Boulder, CO Area Codes
Boulder, Colorado (population 105,689) uses area codes 720, 303 and 983.
Boulder has no telephone exchange of its own in NANPA records; it is served by the Longmont exchange about 20.5 km away.
Carriers with Boulder numbers
64 prefixes are assigned to the Longmont exchange: 31% mobile, 44% VoIP and cable, 25% landline.
| Carrier | Prefixes |
|---|---|
| Lumen (Qwest) | 14 |
| Verizon Wireless | 10 |
| Onvoy (Sinch) | 10 |
| Bandwidth | 8 |
| Lumen (Level 3) | 6 |
| T-Mobile | 6 |
| AT&T Mobility | 4 |
| Telnyx | 1 |
Area codes used in Boulder
| Area code | Prefixes serving Boulder | Main carriers in this code |
|---|---|---|
| 720 | 39 | T-Mobile, Lumen (Qwest), AT&T Mobility |
| 303 | 18 | Lumen (Qwest), Verizon Wireless, Lumen (Level 3) |
| 983 | 7 | Onvoy (Sinch), Wide Voice, AT&T Mobility |
Boulder phone number prefixes
Numbers starting with these first six digits were originally assigned to the Longmont exchange.
720-204Lumen (Level 3)720-340Verizon Wireless720-378AT&T Mobility720-438Onvoy (Sinch)720-442Bandwidth720-453T-Mobile720-487Telnyx720-491AT&T Mobility720-494Lumen (Qwest)720-526AT&T Mobility720-534Vonage720-552Verizon Wireless720-597Verizon Wireless720-600Onvoy (Sinch)720-652Lumen (Qwest)720-680T-Mobile720-684Lumen (Level 3)720-698Verizon Wireless720-713Onvoy (Sinch)720-714Onvoy (Sinch)720-718Lumen (Qwest)720-727Bandwidth720-731Lumen (Level 3)720-743Bandwidth720-745Lumen (Level 3)720-759Bandwidth720-781T-Mobile720-804T-Mobile720-815Comcast (Xfinity)720-818Verizon Wireless720-821Onvoy (Sinch)720-853Bandwidth720-864Lumen (Qwest)720-871T-Mobile720-899Verizon Wireless720-927Bandwidth720-964T-Mobile720-970Bandwidth720-986Bandwidth303-485Lumen (Qwest)303-532Paetec Itel303-651Lumen (Qwest)303-652Lumen (Qwest)303-678Lumen (Qwest)303-682Lumen (Qwest)303-684Lumen (Qwest)303-702Lumen (Qwest)303-709Verizon Wireless303-746Verizon Wireless303-772Lumen (Qwest)303-774Lumen (Qwest)303-775Verizon Wireless303-776Lumen (Qwest)303-827Lumen (Level 3)303-834Verizon Wireless303-845AT&T (Teleport)303-848Lumen (Level 3)983-200Nuso983-207Onvoy (Sinch)983-213AT&T Mobility983-223Onvoy (Sinch)983-226Onvoy (Sinch)983-230Onvoy (Sinch)983-983Onvoy (Sinch)
Nearby cities in area code 720
- Denver
- Aurora
- Lakewood
- Thornton
- Arvada
- Westminster
- Centennial
- Longmont
- Broomfield
- Commerce City
- Littleton
- Brighton
Questions
- What is the area code for Boulder, CO?
- Boulder uses 3 area codes: 720, 303 and 983. They overlay each other, so all of them cover the whole city and you dial 10 digits for local calls.
- What time zone is Boulder in?
- Boulder is in the Mountain time zone.