This three-digit numerical assignment designates a specific geographical region within a telecommunications numbering plan. It is used to route telephone calls to the intended destination within that area. For example, when dialing a number within that region, this numerical code is typically the first set of digits entered.
The allocation of these codes is essential for efficient telephone network operation. These codes facilitate the expansion of telecommunication services. Historically, these were initially introduced to manage increasing demand on the telephone network. The introduction of the three-digit assignment allowed for many unique phone numbers to be assigned in that particular region.