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US area code · Colorado

720 area code

Where the 720 area code is, its overlay and how to dial a +1 720 number from anywhere.

CoversDenver, ColoradoTime zoneMountain (MT)TypeOverlay
Quick answer

The 720 area code is in Denver, Colorado, United States (Mountain (MT)). To call from abroad: +1 720 555-0123. It is an overlay, so all 10 digits are dialled.

StateColorado
Main areaDenver
Time zoneMountain (MT)
TypeOverlay
10-digit dialingRequired
In service since03-Mar-1998

The 720 area code is a geographic North American Numbering Plan (NANP) code covering Denver, Colorado. It has been in service since 03-Mar-1998 and sits in the Mountain (MT) time zone.

Overlay 720 shares its region

Several area codes cover the same geographic area, so two neighbours can have different codes. Because of the overlay, you must dial all 10 digits (area code + number) even for local calls.

720303983

How to dial a 720 number

From abroad+1 720 555-0123
Within the US / Canada1 720 555-0123
Locally (same area)720 555-0123

Cities in the 720 area code

A 720 number is usually in one of these places in Colorado — 12 counties.

Arvada JeffersonAurora Adams;ArapahoeBoulder BoulderBrighton Adams;WeldBroomfield Broomfield;JeffersonCastle Rock DouglasCastlewoodColumbineCommerce City AdamsDenver Adams;Arapahoe;Denver;JeffersonEnglewood ArapahoeHighlands RanchKen CarylLafayette BoulderLakewoodLittleton Arapahoe;Douglas;JeffersonLongmont Boulder;WeldLoveland LarimerNorthglennParker DouglasSouthglennThorntonWestminster AdamsWheat Ridge Jefferson

Other Colorado area codes

303719748970983

Frequently asked questions

Where is the 720 area code?

The 720 area code is in Denver, Colorado, United States (Mountain (MT)).

Is 720 an overlay area code?

Yes. 720 overlays the same region as 303, 983, so callers dial all 10 digits.

Do I have to dial 10 digits for 720?

Yes — dial the area code plus the seven-digit number.

How do I call a 720 number from another country?

Dial your exit code (or +), then 1, then 720, then the number: +1 720 555-0123.

Source: NANPA numbering plan. An area code covers a region, not a precise address — a 720 number does not pinpoint a street or ZIP code.

Number holders in area code 720

Each prefix (the three digits after the area code) is assigned by NANPA to one telephone company. 800 prefixes are in use in 720, shared by 52 companies. The largest holders:

CompanyPrefixesShare
T-Mobile USA, Inc.13217%
Qwest Corporation10313%
New Cingular Wireless PCS, LLC9212%
Cellco Partnership Dba Verizon Wireless759%
Bandwidth.Com CLEC, LLC557%
Onvoy, LLC547%

Source: NANPA central office code assignments. A number keeps its original prefix when it is ported to another carrier.

Complaints about 720 numbers

Reports to the FTC, last 30 days
794
Recorded messages or robocalls
61%
Rank among area codes
#78 of 670
Most reported subjects
Other (357)
Reducing your debt (credit cards, mortgage, student loans) (123)
Dropped call or no message (96)

Period Aug 26 – Sep 24, 2026. These are the numbers shown on the caller ID of the reported calls; many are spoofed and do not belong to the real caller.

Source: US Federal Trade Commission, Do Not Call reported calls data (daily files).

All US area codes United States +1 Map of area code 720 — cities & rate centres

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