Colorado · Mountain Time
Fort Collins, CO Area Codes
Fort Collins is served by 2 area codes (748, 970). Here's which is original, which are overlays, and how to pick one for a new local number.
Last updated October 3, 2026 · Source: NANPA
Area codes serving Fort Collins
Fort Collins sits in Colorado, part of the West region and the Mountain Time zone. Its numbers are spread across an overlay of 2 codes that all cover the same ground: 748, 970.
The original code is 970 (in service since 1995). As the area ran low on numbers, regulators added overlay codes on top instead of splitting the city, so longtime residents kept their numbers while new lines received a newer code.
| Code | Area served | In service |
|---|---|---|
| 748 | Northern and western Colorado including Fort Collins, Greeley, Grand Junction and the mountain resorts | July 7, 2025 |
| 970 | Northern and western Colorado including Fort Collins, Greeley, Grand Junction and the mountain resorts | April 2, 1995 |
Nearby cities sharing these area codes
- Greeley
- Loveland
- Grand Junction
- Windsor
- Durango
- Montrose
- Sterling
- Fort Morgan
- Steamboat Springs
- Glenwood Springs
- Aspen
- Vail
- Estes Park
- Cortez
How to pick an area code for a new number
When you activate a new line in Fort Collins, the carrier assigns whichever code has numbers available — you usually can't choose. If a specific code matters to you (for example the prestige of 970), ask the carrier whether any blocks remain, or request a number transfer. All codes here dial identically and cost the same.
Dialing in Fort Collins
Because Fort Collins is an overlay area, 10-digit dialing is mandatory: always dial the area code plus the seven-digit number, even for a neighbor. From outside the US, dial +1, then the area code and number. See 10-digit dialing and overlay area codes for the background. For every code in Colorado, visit the Colorado area codes page.
Quick answers
Fort Collins area code FAQ
What area codes does Fort Collins use?
Fort Collins, CO is served by 2 area codes: 748, 970.
Which is the original Fort Collins area code?
970 is the original code for Fort Collins, in service since 1995; the others were added later for more numbers.
What time zone is Fort Collins in?
Fort Collins is in the Mountain Time zone.
Do I need to dial the area code in Fort Collins?
Yes. With multiple overlapping codes, 10-digit dialing is required for every call in this area.