Introduction
A 720 area code number tells callers exactly one thing: this business picked up in Denver. Assigned in 1998 as an overlay to the older 303 code, 720 now shares the entire Denver-Boulder footprint with two other prefixes. Skipping a downtown lease doesn't mean skipping the credibility.
This guide breaks down where the code actually reaches today, how Denver's three-code overlay works, and what the metro's business scene looks like right now. We'll also cover how a virtual 720 area code phone number lets a remote team answer and route calls like they're sitting in LoDo.
Where Is the 720 Area Code Located?
The 720 area code covers the Denver-Boulder metro area in Colorado, spanning Denver, Adams, Arapahoe, Boulder, Broomfield, Douglas, and Jefferson counties. It was activated in 1998 as an overlay to the existing 303 code, meaning both prefixes serve the exact same footprint side by side.
A third overlay, 983, joined the mix in 2021 as demand kept climbing across the metro. That's three active codes stacked over one region, a sign of just how fast Colorado's Front Range has grown since 303 first covered the whole state back in 1947.
From a Single Statewide Code to a Three-Way Overlay
303 originally covered all of Colorado before regional splits carved out 719 for Colorado Springs and 970 for the mountain and rural north. What remained around Denver eventually needed two more overlays just to keep pace with new lines.
Porting a Number Into the Denver Overlay
If your business already carries a 303 or 983 number, you can add a 720 line without giving up the original. letsdial ports existing numbers in for free, both directions, so switching providers never means losing a number your customers already know. More detail sits on our virtual 720 area code phone number page.
Cities and Communities Covered by the 720 Prefix
720 numbers issue across the Denver-Boulder metro rather than a single town, since the overlay spans several counties at once. Here's where a local number puts your business on the map:
- Downtown Denver & LoDo — Corporate HQs, breweries, convention business
- Cherry Creek — Retail, finance, professional services
- RiNo & Five Points — Creative agencies, startups, arts district
- Boulder — Tech, biotech, University of Colorado
- Aurora & Lakewood — Aerospace, healthcare, logistics
- Arvada & Westminster — Growing suburban business corridor
Every city on that list shares the same overlay pool with 303 and 983, so a number issued in Boulder looks identical to one issued in Cherry Creek. For a growing business, that consistency matters more than the exact block it sits on.
A law firm downtown, a biotech startup in Boulder, and an aerospace supplier in Aurora all dial out and answer in on the same 10-digit format, which keeps onboarding simple no matter which part of the metro a team actually sits in. More detail sits on our intelligent call routing page.
Time Zone and Dialing Format for Denver Numbers
Every number on this exchange runs on Mountain Time, UTC-7 in winter and UTC-6 during daylight saving, one hour ahead of the West Coast and two behind the East. A 9 a.m. call placed from New York lands at 7 a.m. on a Denver desk.
- Country code: +1
- Area code: 720
- Local number: XXX-XXXX
- Full dial-out: +1-720-XXX-XXXX
- Local dialing rule: 10-digit required across 303 / 720 / 983
Skip a digit and the call simply won't connect, even between two desks in the same building. Voice quality doesn't change based on which of the three overlay codes a number carries, so there's no technical downside to picking 720 over the older 303.
Calling a 720 Number From Outside the United States
Reaching a Denver line from abroad follows the standard North American pattern: exit code, then country code 1, then the area code, then the seven-digit local number.
For a caller in Dubai that's 00, then 1, then 720, then the line. Drop any leading zero — North American numbers never take one. Get the sequence right and the call rings through to Denver as cleanly as one placed from across the street.
Every Code in the Overlay Shares One Dial-In Format
Whether a line answers on 303 / 720 / 983 doesn't change how an international call reaches it — every code sharing this territory uses the identical +1 format, so getting the area code right matters far more than knowing which specific prefix a business happens to hold.
The Business Landscape Behind Denver's Local Numbers
Denver anchors an aerospace corridor locals call Aerospace Alley. Lockheed Martin, United Launch Alliance, and Ball Aerospace all run major operations inside the metro, alongside a federal research presence that includes NREL just up the road in Golden.
Beyond aerospace, the region runs on energy, craft brewing, and outdoor recreation. Downtown Denver houses oil and gas headquarters and a brewing scene dense enough to earn the city the nickname the Napa Valley of beer.
A Fast-Growing Tech Scene Along the Front Range
Boulder and Denver together have built a real tech cluster sometimes called Silicon Mountain, with software and biotech firms drawn by the university pipeline and a lower cost base than the coasts.
What This Means for a New Business Line
A local number signals you're inside that density, not calling in from somewhere else. For sales teams targeting Colorado accounts or support desks fielding Denver clients, an out-of-state prefix is often the reason a call gets screened before it even rings twice.
Outdoor Recreation and Cannabis Round Out the Mix
Denver's outdoor gear and recreation companies lean on the Front Range's ski and trail access, while the state's legal cannabis industry, headquartered largely in the metro, adds a fast-growing category of retail and logistics callers few other area codes see.
Remote Teams Are Driving Demand for Local Numbers
Plenty of the businesses picking up Denver numbers today have no office in the metro at all. A distributed sales team can carry a 720 line the same way it carries a Slack workspace: as one more tool that follows the person, not the building.
Why Your Business Needs a 720 Area Code Virtual Number
Caller-behavior data consistently shows unfamiliar area codes get ignored. A local 720 number changes that instantly for Denver-based leads, giving you metro credibility without paying for a downtown office, and letting your team answer from anywhere with an internet connection.
letsdial issues a virtual 720 area code phone number in minutes, no hardware and no on-site line required. Every plan includes intelligent call routing that sends Denver callers straight to the right rep, plus an AI receptionist that answers, books, and logs the call to your CRM after hours.
- Pick a Denver number and go live in under 3 minutes, no credit card required
- Port an existing 303, 720, or 983 number in for free, both directions
- Every call transcribed automatically, with AI summaries attached in seconds
- One login covers calling, SMS, video, and team chat for the whole Denver line
- SOC 2 Type II, HIPAA, and PCI DSS compliance on every plan, not a bigger-plan perk
Setup runs through letsdial's UCaaS platform, so the same login also carries team chat, SMS, and video, one invoice instead of five vendor bills for a Denver presence. A remote rep in Fort Collins and a support agent in Aurora can both answer the same 720 line without either one owning a desk phone, and a Boulder-based founder can run the whole setup from a laptop between meetings.
Pricing starts at $7.99 per user per month on the Starter plan, billed annually, with unlimited US and Canada calling and a Denver number included from day one. There's no separate charge for the AI receptionist minutes bundled into every paid tier, so a busy front desk doesn't rack up a surprise invoice. That record is published in full as public record for area code 720.
The Bottom Line on Getting a Denver Number
A 720 area code number puts your business inside Denver's neighborhoods without a Denver lease, the kind of local presence Cherry Creek, LoDo, and Boulder callers actually pick up for. letsdial turns that number into a full phone system, AI receptionist included, under one login, so start the free trial today and claim your Denver number before a competitor does.
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Written by Aryan Khan · July 3, 2026
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