Area Code Atlas

NANP-Split of the 602 (Arizona) Numbering Plan Area (NPA) and the Addition of the 480 and 623 NPA's

NPA 480 split from 602

Area code 480 was created on March 1, 1999, as part of a three-way split of area code 602. The new code served the East Valley of the Phoenix metropolitan area.

NPA 480 split from 602

Area code 480 was created on March 1, 1999, as part of a three-way split of 602. The new code served the East Valley of the Phoenix metropolitan area, while 602 was retained for central Phoenix.

Introduction of overlay area code 480 in Phoenix East Valley

On April 1, 1999, area code 480 was introduced as an overlay for the East Valley region of Phoenix, Arizona, requiring ten-digit dialing for local calls.

Permissive dialing begins for new area codes 480 and 623

Permissive dialing of the new area codes 480 and 623 began on April 1, 1999, allowing callers to use either the old 602 or the new codes during the transition period.

Urgent reminder to update networks for the 602 NPA Split in Phoenix, Arizona with the new 623 and 480 NPAs

Mandatory ten-digit dialing implemented in 480

Area code 480 transitioned to mandatory ten-digit dialing by October 24, 2021, due to the nationwide designation of 988 as the National Suicide Prevention Lifeline dialing code, which conflicted with seven-digit dialing.

Boundary elimination overlay for 602, 480, and 623 approved and planned

The Arizona Corporation Commission approved a plan on November 9, 2021, to eliminate area code boundaries among 602, 480, and 623, creating a unified overlay complex for the entire Phoenix metropolitan area to address number exhaustion. This plan was followed by activation of the overlay in 2023.

NPA 480, 602 and 623 Boundary Elimination Overlay (Arizona)

Overlay complex activated for 602, 480, and 623 in 2023

The overlay complex for area codes 602, 480, and 623 was activated on September 12, 2023, removing boundaries within the Phoenix metropolitan area and requiring ten-digit dialing throughout the region, allowing new central office codes to be assigned across the entire area.

Arizona overlay complex implementation and mandatory 10-digit dialing

The overlay complex involving area codes 602, 480, and 623 was implemented in September 2023, making ten-digit dialing mandatory across the Phoenix metropolitan area, following relief planning and regulatory approval in 2021.