Area code 720 serves as an overlay for the vibrant state of Colorado, covering the same geographic expanse as the original 303 area code. This numbering plan area encompasses the Denver-Aurora-Lakewood Metropolitan Statistical Area, extending into surrounding counties to manage the burgeoning demand for telephone numbers. Introduced in 1998, this overlay was specifically designed to ensure the region could support future growth without the disruption of splitting existing area codes, thereby maintaining geographic continuity for residents and businesses.
Geographic Coverage and Location
When asking "what area code 720," one must understand its relationship to the 303 area code. The 720 area code blankets the state of Colorado, sharing the same boundaries as its predecessor. This includes the core cities of Denver, Boulder, Aurora, and Westminster, as well as the suburban communities of Adams, Arapahoe, Broomfield, Douglas, and Jefferson counties. Essentially, any call within this vast region can utilize the 720 prefix, making it a ubiquitous part of the Centennial State’s telecommunications landscape.
History and Implementation
The history of 720 is rooted in the exhaustion of the original 303 numbering plan. As mobile phones, fax machines, and pagers became ubiquitous in the late 20th century, the need for new numbers surged. Rather than dividing the densely populated Denver area with a new code, regulators chose an overlay. The 720 area code was officially activated in 1998, requiring ten-digit dialing (area code + seven-digit number) for all local calls. This method preserved existing phone numbers and simplified the process for residents who did not have to change their established contact information.
Significance of an Overlay Code
Understanding the significance of an overlay code is key to answering "what area code 720." Unlike a geographic split, an overlay does not fragment the region; it layers on top of it. This approach offers distinct advantages, primarily the conservation of the existing 303 prefix for new subscribers. It eliminated the need for boundary changes and the associated costs of printing new checks, licenses, and business materials. For the average user, it simply means that neighbors, colleagues, and local businesses might have numbers starting with either 303 or 720, depending on when they originally obtained their service.
Ten-Digit Dialing Requirement
One of the most noticeable impacts of the 720 overlay is the universal implementation of ten-digit dialing. Since the area codes cover the same territory, local calls must now include the area code to route properly. This means dialing "303-XXX-XXXX" or "720-XXX-XXXX" for every call, even if the neighbor next door has a different prefix. This technical requirement is a direct result of the overlay system and is essential for the continued functionality of the telephone network in the region.
Business and Professional Context
For businesses operating in Colorado, the 720 area code carries the same weight as 303. A number with a 720 prefix signals that the company is local to the Denver metropolitan area, which can instill trust in customers. Many companies choose to port their existing 303 numbers to 720 when updating their systems or expanding lines, ensuring brand consistency. The availability of both codes means that a startup can acquire a "fresh" 720 number while an established firm might retain its classic 303 digits.
