All 5 Colorado Area Codes
Every active code: tap any card for its full guide, who called, cities and ZIPs, map, spam patterns and local time.
Got a call from a Colorado number you don’t recognize?Open that code’s guide above for its full prefix lookup. AT&T ActiveArmor® blocks spam automatically, included with AT&T wireless plans.
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Included with AT&T wireless plans. Requires compatible device/service and download of the AT&T ActiveArmor® app. Other terms & restrictions apply. May not detect all threats and may block wanted calls. Some features require Advanced mobile security ($7/mo.). See terms.
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Service good for 30 days. Data: Limited to 100GB of data and 25GB of hotspot data. No additional data is available after limit is reached. Video is limited to SD quality. Talk & Text: Includes unlimited talk & text within the U.S. and unlimited text from the U.S. to over 230 countries. Limits: One trial per user. An unlocked, dual eSIM iPhone is required. You’ll receive a trial phone number that belongs to AT&T and is not available to be ported to another carrier or otherwise retained. Trial plan features and details may differ from or be unavailable in other AT&T plans. U.S. only. All terms subject to change at any time.
Why Metro Denver Has 3 Area Codes
When a region uses more numbers than one code can hold, new codes are overlaid on the same territory rather than forcing anyone to change numbers. Metro Denver now uses 303, 720 and 983: same neighborhoods, ten-digit dialing, and every one of them covered by its own guide above.
Colorado Area Codes by City
The largest Colorado communities and the area codes that serve them. Every city links to its local AT&T internet page.
How Colorado Got Its Codes
Every Colorado area code, in the order it entered service. Splits carved new regions; added codes overlay existing ones, which is why ten-digit dialing is standard.
| In service | Code | How it arrived |
|---|---|---|
| 1947 | 303 | One of the original area codes of 1947 |
| 1988 | 719 | Split from 303 |
| 1995 | 970 | Added to the 303 region |
| 1998 | 720 | Added to the 303 region |
| 2022 | 983 | Added to the 303 region |
Source: NANPA NPA database, July 2026. Regenerated monthly.
Colorado Area Code Map
Every active Colorado area code at a glance, anchored to the metro each one serves. Tap any code above for its detailed coverage map.
Explore the interactive map
Click any region to open that area code's full guide. Hover for county names.
Open the printable Colorado area code map (PDF) - poster format with a QR code back to this page.
Internet, wireless & stores across the state
AT&T Home Internet in Colorado
AT&T home internet is available across Colorado, checked address by address; every area code guide above lists its cities and what’s offered there.
AT&T Fiber: Ltd. avail/areas. Speeds based on wired connection. Actual speeds vary. For 5-GIG, single device wired speed maximum 4.7Gbps. For more info., visit att.com/speed101.
Start with home internet in Colorado, or pair it with wireless in an internet + wireless bundle.
AT&T Wireless in Colorado
AT&T’s 5G network covers most of Colorado. ActiveArmor® spam blocking is included with every unlimited plan, your number stays yours when you move between Colorado codes, and great cell phone deals in Colorado are a tap away.
AT&T may temporarily slow data speeds if the network is busy. 5G req’s compatible plan & device. Coverage not available everywhere. Learn more at att.com/5Gforyou.
AT&T Stores Across Colorado
From the Colorado Springs metro to Lone Tree, Denver and beyond, walk in for switching, porting, upgrades and hands-on help. Every area code guide lists its nearest stores.
Find stores in: Colorado Springs · Lone Tree · Denver · Lakewood · Aurora
