The 720 area code is located in Colorado, United States, primarily serving Denver, Aurora, Boulder, Lakewood, and surrounding communities along the Front Range. It belongs to the Denver metropolitan telephone service region and shares its geographic coverage with the 303 and 983 area codes.
If you receive a call from a phone number beginning with 720, the number is associated with Colorado’s Denver-area numbering region. However, the caller may not physically be in Colorado because mobile numbers can travel with their owners, and internet-based phone services can operate from almost anywhere.
This guide explains where the 720 area code is located, which cities it covers, its time zone, dialing requirements, and how to identify potentially suspicious calls.
Where Is the 720 Area Code Located?
The 720 area code serves north-central Colorado, particularly the Denver metropolitan area and nearby Front Range communities. Its coverage includes parts of several counties, such as Denver, Arapahoe, Adams, Jefferson, Boulder, Douglas, and Broomfield.
The region includes major employment centers, residential suburbs, universities, government offices, and commercial districts. Both businesses and individuals use 720 phone numbers for mobile phones, landlines, and VoIP services.
Quick Facts About Area Code 720
| Feature | Details |
|---|---|
| Area code | 720 |
| State | Colorado |
| Country | United States |
| Main city | Denver |
| Other major cities | Aurora, Boulder, Lakewood, Thornton |
| Time zone | Mountain Time |
| Standard time | MST (UTC−7) |
| Daylight saving time | MDT (UTC−6) |
| Overlay area codes | 303 and 983 |
| Introduced | September 1, 1998 |
| Country calling code | +1 |
A 720 phone number indicates the number’s assigned geographic numbering area, not necessarily the caller’s current location.
What Cities Use the 720 Area Code?
The 720 area code covers Denver and numerous surrounding communities. Because it operates as an overlay, a city may have phone numbers beginning with 303, 720, or 983.
Some of the principal cities and communities associated with the 720 numbering region include:
| City | County or counties |
|---|---|
| Denver | Denver |
| Aurora | Arapahoe, Adams, Douglas |
| Boulder | Boulder |
| Lakewood | Jefferson |
| Thornton | Adams, Weld |
| Arvada | Jefferson, Adams |
| Westminster | Adams, Jefferson |
| Centennial | Arapahoe |
| Littleton | Arapahoe, Jefferson, Douglas |
| Broomfield | Broomfield |
| Englewood | Arapahoe |
| Longmont | Boulder, Weld |
| Parker | Douglas |
| Commerce City | Adams |
| Brighton | Adams, Weld |
The area code also serves other municipalities and unincorporated communities within its geographic boundaries. Not every location in these counties necessarily uses 720, since telephone numbering boundaries do not always follow county lines.
What Time Zone Is Area Code 720 In?
The 720 area code uses the Mountain Time Zone, which observes Mountain Standard Time during winter and Mountain Daylight Time during the daylight saving period.
| Time period | Time zone | UTC offset |
|---|---|---|
| Standard time | Mountain Standard Time (MST) | UTC−7 |
| Daylight saving time | Mountain Daylight Time (MDT) | UTC−6 |
Colorado generally switches to daylight saving time on the second Sunday in March and returns to standard time on the first Sunday in November.
For example, when it is 12:00 PM in Denver, it is 2:00 PM in New York and 11:00 AM in Los Angeles. These differences remain consistent during most of the year because the three locations follow the same daylight saving schedule.
Best Time to Call a 720 Number
For personal or business calls, a reasonable window is usually between 9:00 AM and 6:00 PM Mountain Time, unless the recipient has provided different availability.
If you are calling from another country, check the current Denver time rather than assuming Colorado always stays at UTC−7. The daylight saving transition changes the offset for part of the year.
History of the 720 Area Code
The 720 area code was introduced in 1998 to provide additional telephone numbers in the rapidly developing Denver region.
Previously, the 303 area code served the Denver area and a much larger portion of Colorado. As demand for telephone numbers increased, numbering administrators introduced 720 as an overlay of 303.
An overlay allows multiple area codes to serve the same geographic region without requiring existing customers to change their telephone numbers.
Timeline of Denver Area Codes
1947: Area code 303 established
Colorado received 303 as one of the original North American area codes.
1998: Area code 720 introduced
The new code provided additional telephone numbering capacity in the Denver region.
2022: Area code 983 introduced
A third area code joined the existing 303/720 overlay, with 983 numbers becoming available in June 2022.
The introduction of additional area codes reflects the continuing need for telephone numbers as the Denver metropolitan region grows.
What Is the Difference Between 303, 720, and 983 Area Codes?
The 303, 720, and 983 area codes cover the same general Denver-region geographic area. Their main difference is when they were introduced, not the neighborhoods or cities they serve.
| Area code | Introduced | Main distinction |
|---|---|---|
| 303 | 1947 | Original area code |
| 720 | 1998 | First overlay |
| 983 | 2022 | Additional overlay |
All three codes use Mountain Time and the same 10-digit local dialing system. A 720 number does not automatically indicate that a person lives farther from downtown Denver than someone with a 303 number.
Similarly, a 983 number is not necessarily a mobile number or a business number. The telephone service type depends on the provider and number assignment.
How to Call a 720 Area Code Number
Calling a 720 number is straightforward, but the dialing format depends on whether you are calling from within the United States or another country.
Calling Within the United States
Dial the complete 10-digit telephone number:
720-XXX-XXXX
For example, if a business provides a 720 phone number, enter all ten digits, even when you are calling from another phone in Denver.
Local calls within the 303/720/983 region require 10-digit dialing. The number of digits you dial does not by itself determine whether a call is billed as local or long-distance.
Calling From Outside the United States
Use the United States country code, +1, followed by the full number:
+1 720 XXX XXXX
The plus sign represents the international dialing prefix appropriate to your phone service.
International calling charges may apply depending on your provider and plan. Calls made through internet-based applications may have different pricing arrangements.
Calling With a Mobile Phone
Save the number in international format, such as +1 720 XXX XXXX, especially if you travel internationally. This makes the number easier to dial across countries without changing its saved format.
Is the 720 Area Code a Scam?
No. The 720 area code is legitimate, and many Colorado residents, organizations, and businesses use it. However, scammers can place calls that appear to originate from 720 numbers.
Caller ID spoofing allows someone to display a number that is different from the number actually originating the call. A scammer might use a familiar Colorado area code to make the call seem local and trustworthy.
Common Warning Signs of Suspicious Calls
Be cautious when a caller:
- Requests your banking password, verification code, or Social Security number.
- Claims you must pay immediately to avoid arrest or account suspension.
- Demands payment through gift cards, cryptocurrency, or unusual payment methods.
- Claims to represent a government agency but refuses independent verification.
- Sends an unexpected link asking you to enter sensitive information.
- Repeatedly calls without leaving a meaningful message.
These warning signs are not specific to Colorado. They apply to suspicious calls from any area code.
What to Do if an Unknown 720 Number Calls You
If you do not recognize the number, allow the call to go to voicemail when practical. Legitimate callers may leave their name, organization, and reason for contacting you.
If someone claims to represent your bank, insurance provider, utility company, or government agency, end the call and contact the organization using a number from its official website or your account documents.
You can also block repeated unwanted calls and report suspected fraud to the Federal Trade Commission.
A reverse phone lookup may help identify a business or previously reported caller, but results can be incomplete or outdated. The displayed number alone cannot establish the caller’s identity.
Can You Get a 720 Area Code Phone Number?
Yes. Individuals and businesses may be able to obtain a 720 number through mobile carriers, landline providers, or VoIP telephone services, depending on number availability.
Having a 720 number can be useful for a company that wants a Denver-area telephone presence, including businesses operating remotely or serving Colorado customers.
Options for Getting a 720 Number
| Phone service | Suitable for | Main consideration |
|---|---|---|
| Mobile carrier | Personal or business mobile use | Available numbers vary by carrier |
| Traditional landline | Fixed-location telephone service | Installation and service area restrictions may apply |
| VoIP provider | Remote teams and virtual business lines | Requires compatible service and internet connectivity |
| Business phone system | Multiple employees and departments | Features and monthly charges vary |
Before selecting a provider, check whether it offers available 720 numbers, supports number portability, and provides the calling features you need.
Can You Keep Your 720 Number if You Move?
Often, yes. Mobile and VoIP customers can generally retain an existing number when moving to another city or state, provided their service remains compatible.
Number portability also allows many customers to transfer a number between eligible providers. However, some landline transfers and changes in service area may be restricted.
This is one reason a 720 number does not prove that its owner currently lives in Colorado.
How to Identify the Location of a 720 Phone Number
The area code provides the broad numbering region, but the next three digits can sometimes offer more specific information about the number’s original assignment.
A standard North American phone number follows this structure:
720-XXX-XXXX
- 720: The area code identifying the Denver-area numbering region.
- XXX: The three-digit central office prefix associated with a numbering assignment.
- XXXX: The four-digit line number.
The three-digit prefix following 720 is also known as the central office code or NXX. Numbering assignment records may associate prefixes with telephone providers and rate centers.
However, because numbers can be transferred between providers and retained after relocation, the original assignment does not necessarily reveal the present carrier or physical location of the person using the number.
Frequently Asked Questions About the 720 Area Code
1. What state is the 720 area code in?
The 720 area code is in Colorado, United States. It primarily serves Denver, Aurora, Boulder, and surrounding communities in the north-central part of the state.
2. Is 720 a Denver area code?
Yes. Denver is the principal city associated with the 720 area code. The code also serves numerous surrounding suburbs and communities in the Denver metropolitan region.
3. Is the 720 area code in California?
No. The 720 area code belongs to Colorado, not California. Although California also uses several area codes beginning with 7, including 707 and 714, 720 is assigned to the Denver region.
4. Are 720 phone numbers cell phones or landlines?
A 720 number may belong to a mobile phone, landline, or VoIP service. The area code alone cannot identify the type of phone service. A carrier lookup may provide additional information, although number portability can affect its accuracy.
5. Is calling a 720 number free?
Not necessarily. Calling costs depend on your telephone plan, location, and service provider. Many U.S. mobile plans include domestic calling, but international calls or certain services may carry additional charges.
6. Can someone outside Colorado have a 720 number?
Yes. Someone who originally obtained a 720 number in Colorado may keep it after moving elsewhere. Businesses can also use virtual telephone services to obtain Denver-area numbers without maintaining a physical office there.
Conclusion
The 720 area code serves Denver and surrounding communities in Colorado, sharing its coverage with the 303 and 983 area codes. It operates in the Mountain Time Zone, requires 10-digit dialing for local calls, and is used for mobile, landline, and internet-based telephone services.
If you receive an unfamiliar call from a 720 number, remember that the area code identifies the number’s assigned region rather than the caller’s verified location or identity. Check the caller independently before sharing personal information or making payments.
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