520

Area code 520 is an integral part of the telecommunication landscape in the United States, specifically serving the state of Arizona. Geographical Coverage and Establishment: Area code 520 primarily serves the southern part of Arizona, including significant cities like Tucson and Nogales. This area code was established on March 19, 1995, following a split from the then sole area code for Arizona, 602. The need for this new area code arose from the growing demand for phone numbers in the region​​. Designation and Dialing Pattern: The area code 520 is categorized as a General Purpose Code under the North American Numbering Plan (NANP). It was officially assigned on January 21, 1994, before going into service in 1995. For local calls within the same Numbering Plan Area (NPA), the dialing pattern requires a seven-digit number (7D)​​. Population Coverage and Time Zone: This area code is unique to its geographic region, with no overlays, meaning it is the only area code serving its designated areas. It caters to a population of approximately 6.7 million people. Area code 520 operates in the Mountain Standard Time Zone (MST), aligning with GMT -07:00​​. In conclusion, area code 520 plays a vital role in connecting communities in southern Arizona. Established to accommodate the expanding need for telephone numbers, it covers key cities and a significant population, all within a single time zone. This area code represents not just a series of numbers, but a vital communication link for residents and businesses in this part of Arizona.