Area Code 720: Get a Denver Phone Number

720 · Denver

What is the area code for Denver?

The area code for Denver, Colorado is 720, with overlay codes 303, 983 sharing the same geographic footprint. The 720 area code is a North American Numbering Plan geographic code assigned in 1998, covering the Denver-Boulder Metro region. It serves approximately 3,500,000 residents on the Mountain Time (MT) (UTC-7 / UTC-6 DST).

The 720 area code has 786 assigned central-office prefixes (NXX codes, the three digits after the area code) across 12 rate centers, with numbers allocated to roughly 55 carriers.

At 786 of the ~792 usable central-office prefixes, the 720 area code has about 99% of its numbering capacity assigned, and that near-exhaustion is part of why overlay codes 303, 983 were added to the region. See how 720 compares in our NXX prefix allocation analysis across 338 US area codes. (Prefix data: localcallingguide.com / NANPA, 2026.)

Where is area code 720? Location and map area

Area code 720 is located in Colorado, the United States. Its coverage area centers on Denver and spans the Denver-Boulder Metro region. If you received a call from a 720 number, the caller's number was assigned in this area — though with number porting and virtual numbers, the person may be calling from anywhere.

The 720 location sits in Mountain Time (MT), so local business hours run roughly 9 a.m.–5 p.m. MT. Neighboring Colorado area codes include 303, 719, 970.

For the full story — every city covered, overlay history, and local scam patterns — read the complete Denver area code guide.

All Denver area codes

Denver is served by 3 area codes across the metro area. 720 is the 1998 addition; the others were added as overlays or for surrounding suburbs.

• 303 — Denver — 1947 original
• 720 (current page) — Overlay on the same metro, assigned 1998
• 983 — Overlay on the same metro, assigned 2022

Cities served by the 720 area code

The 720 area code covers 5 major cities and towns across the Denver-Boulder Metro region (CO):

Businesses across Denver and surrounding cities use 720 numbers to project local presence and lift call answer rates. Industry studies of local presence dialing consistently report answer-rate gains of 20–40% over toll-free or out-of-area numbers — a caller ID that matches the recipient's region looks familiar and gets picked up.

720 area code time zone and business hours

The 720 area code is in the Mountain Time (MT) zone (UTC-7 / UTC-6 DST). Standard business hours in 720 run 9 AM to 5 PM MT.

If you're calling into 720 from a different time zone, factor in the offset. For example, an Eastern Time business calling 720 at 9 AM ET reaches Denver at 7 AM MT — likely outside standard business hours.

History of the 720 area code

The 720 area code was introduced in 1998 when the North American Numbering Plan was first deployed. As Denver grew and number demand increased, overlay codes 303, 983 were added to serve the same geographic region — a common solution that avoids forcing existing subscribers to change their numbers.

• 1947 303 added to serve the same region
• 1998 720 entered service
• 2022 983 added to serve the same region

Is the 720 area code safe? Spam and scam calls

720 is a legitimate geographic area code for Denver — it is not a scam code or a premium-rate prefix, and a call from a 720 number is most likely a genuine local caller. The risk is not the area code itself but a tactic called neighbor spoofing: scammers fake their caller ID so an unwanted call appears to come from your own area code, because people answer familiar numbers more readily.

If you get an unexpected 720 call, a few signals point to a likely scam — a pre-recorded message, urgent pressure to act now, a demand for payment by gift card or wire transfer, or anyone asking for passwords, Social Security, or account numbers. Let suspicious calls go to voicemail, never share personal information, and report fraud to the FTC at reportfraud.ftc.gov.

The FCC consumer guide on spoofing explains your rights under the Truth in Caller ID Act. A real Denver business will leave a clear voicemail and will not pressure you.

US carriers verify caller ID with the STIR/SHAKEN framework, which flags many spoofed numbers as "Spam Likely" before they ring. DialPhone 720 numbers are registered for STIR/SHAKEN attestation, so calls from your business are verified as genuine and reach customers without a false spam label. See the DialPhone guide to VoIP security for more.

Why get a 720 area code number for your business?

Getting a 720 number gives your business three measurable advantages over a toll-free or out-of-area number:

1. Local trust signal. Customers in Denver recognize 720 as their home area code. Caller ID matching builds immediate credibility for service businesses, sales outreach, and patient communication.
2. Higher answer rate. Calls from a familiar local area code are answered far more often than unknown or toll-free numbers — industry measurements of local presence dialing put the lift at 20–40%, which matters most for outbound sales, appointment confirmations, and time-sensitive service callbacks.
3. Targeted marketing. Businesses serving Denver and the broader Denver-Boulder Metro can advertise a local number across print, radio, billboards, and digital channels for higher conversion than a national 800 number.

For businesses in Denver and surrounding cities, top industries that benefit from local 720 presence include Professional Services, Healthcare, and Retail. DialPhone's AI receptionist is available for every 720 number — never miss a call, even after standard business hours.

How to get a 720 area code number

Setting up a 720 business number with DialPhone takes under 10 minutes:

1. Sign up for a DialPhone plan. Choose any plan starting at $24/user/month. Free 14-day trial, no credit card required.
2. Search available 720 numbers. Filter the DialPhone number inventory by area code, city, or pattern.
3. Choose your number and configure. Assign your new 720 number to a user or team, set up call routing, voicemail, AI receptionist, and business SMS.
4. Port your existing number (optional). Already have a 720 number? Free number porting in 2 to 5 business days with zero service interruption.

New to local numbers? The complete guide to getting a local phone number covers choosing the right area code, porting an existing line, and avoiding spam flags.

720 area code overlay codes

The Denver-Boulder Metro region is served by multiple overlay area codes:

Area Code	Coverage
720	Primary area code for Denver-Boulder Metro, assigned 1998
303	Overlay — same geography (assigned 1947)
983	Overlay — same geography (assigned 2022)

All overlay codes serve the same Denver region. New subscribers may be assigned any available code; existing numbers retain their original prefix.

AI receptionist for 720 area code businesses

Every DialPhone 720 number includes optional AI receptionist coverage, available 24/7. The AI handles calls when your team is unavailable — answering common questions, booking appointments, routing urgent callers to on-call staff, and capturing voicemail with full transcription and intent tagging.

For businesses in Denver that handle high call volume, run extended hours, or need bilingual support (especially valuable in service areas with diverse customer bases), the AI receptionist reduces voicemail backlog and improves first-call resolution.

All area codes in Colorado

Colorado has 5 active geographic area codes. The 720 area code is part of the same numbering plan as the codes listed below — calls between them are typically local within the state, depending on the carrier.

Nearby area codes

Related area codes in Colorado and the Mountain Time (MT) region:

• 303 area code — Denver, Colorado
• 719 area code — Colorado Springs, Colorado
• 970 area code — Fort Collins, Colorado
• 983 area code — Denver, Colorado
• 208 area code — Boise, Idaho
• 307 area code — Cheyenne, Wyoming

All Colorado area codes → · Browse all US area codes →

More area codes: ← 719 Colorado Springs · 724 New Castle →

How this page is verified

DialPhone re-verifies every area code page every 90 days. Area code geography, timezone, and overlay data come from the official North American Numbering Plan Administration (NANPA) database. Pricing reflects the published DialPhone plan tiers — see the pricing page for current details. Number availability varies; check the DialPhone signup flow for live inventory in the 720 region.

What to know before getting a 720 number

• Number availability is finite. Popular Denver area codes can be inventory-constrained — request specific vanity patterns early.
• Porting timing varies. Most 720 ports complete in 2-5 business days; complex multi-line legacy contracts can take 7-10.
• HIPAA tier required for healthcare. The Core $24 plan doesn't include a BAA — healthcare users need Advanced ($34) or above.