303
The Complete Guide to Colorado's Original Phone Code
The 303 area code covers Denver and the Front Range, Colorado's original numbering plan now sharing territory with the 720 overlay. See coverage, history, and how to get a local number.
CO · 4 Area Codes
Colorado
Area Codes
Colorado's economy leans on aerospace, tech, and outdoor recreation, centered around Denver, Colorado Springs, and Aurora. Get a local virtual phone number with any Colorado area code.
4 area codes
Original code 303 · 1947
Capital: Denver
Carrier-grade network
// Why CO Virtual Numbers
Why businesses choose a Colorado virtual number
A local Colorado number shows callers which part of the state you serve.
1947
303 first assigned
303 came first, in 1947
303 was Colorado's original area code, assigned in 1947. The newest, 720, arrived in 1998. Each of the 4 codes below maps to its own part of the state, so the code you pick shows which region you serve.
01 — Colorado at a Glance
Colorado, by the numbers.
Colorado received a single area code, 303, in 1947. It stayed statewide for four decades until 719 split off in 1988, covering Colorado Springs, Pueblo, and the south.
In 1995, 970 split off to cover the northern mountains, western slope, and rural plains, leaving 303 focused on the booming Denver metro.
Rather than split Denver again, regulators overlaid 720 onto 303's territory in 1998 — one of the first overlays in the US, requiring 10-digit dialing.
Did you know?
Colorado's 720, added in 1998, was one of the first overlay area codes in the entire United States — instead of redrawing Denver's map, it simply stacked a second code on the same territory as 303.
// 4 area codes
Colorado Virtual Phone Numbers
Select any area code to get a local virtual number for that region of Colorado.
719
Colorado Springs Business Phone Guide
The 719 area code covers Colorado Springs, Pueblo & southeastern Colorado. Explore its 1988 split from 303, time zone, scam alerts & how to get a local business number.
720
The 720 area code covers Denver and the Front Range in Colorado. Learn its history, the 303 and 983 overlays, time zone, and how to get a number for your business.
970
See which Colorado cities the 970 area code covers, learn the mandatory dialing rules, and find out how the new 748 overlay affects your number starting 2026.
// Get Started
Get a Colorado number in 3 steps
From choosing a code to setting up call routing.
- 01Step 01
Choose a CO area code
Browse the Colorado area codes above and pick the region that best serves your customers.
- 02Step 02
Select your number
Choose from the numbers available in your selected area code.
- 03Step 03
Set up routing
Configure call routing, business hours, and voicemail from your Rozper dashboard for your Colorado number.
Frequently Asked
Colorado number questions answered.
Everything you need to know before getting a Colorado virtual phone number.
Colorado has 4 active area codes: 303, 719, 720, 970. Rozper offers virtual phone numbers in these codes, which you can browse and choose from one dashboard.
303 is Colorado's original area code, assigned in 1947. The most recent addition, 720, followed in 1998.
No. Virtual numbers are location-independent. A business based anywhere in the U.S. or internationally can get a Colorado area code and route calls to any device, team, or call center.
Colorado's capital is Denver, and the state keeps Mountain time. Its population is about 5,957,000, across 64 counties.
Colorado's economy centers on aerospace, tech, and outdoor recreation, with Denver, Colorado Springs, and Aurora as the main business hubs. Colorado has the highest mean elevation of any US state.
Questions about Colorado numbers? Get in touch.
// Next door
States that border Colorado
Customers and teams near the Coloradoline often use a neighbouring state's codes. Here are the area codes next door.
Ready for a Colorado number?
Pick a Colorado area code and talk to us about setting up your number.