Area Code 464 – Atsugi, Kanagawa

Overview of Area Code 464

Area code 464 is a geographic numbering plan area (NPA) within the Japanese telephone numbering plan, specifically designated for the city of Atsugi and its surrounding municipalities in Kanagawa Prefecture. This code is part of the North American-style overlay system implemented in Japan, where multiple area codes serve the same geographic region. The 464 code overlays the traditional 046 code, which originally covered the same region. As a result, local calls within the Atsugi area require 10-digit dialing (area code + subscriber number) even for calls within the same city.

Geographic Coverage and Administrative Jurisdiction

The 464 area code serves Atsugi-shi (Atsugi City) and the neighboring towns of Aikawa and Miyake in the Kōza District of Kanagawa Prefecture. Atsugi is a significant urban center located in the central part of Kanagawa, approximately 50 kilometers southwest of Tokyo. The region is known for its industrial base, including electronics and precision machinery, as well as the Atsugi Naval Air Facility, a joint Japan-U.S. military installation. The administrative jurisdiction falls under Kanagawa Prefecture, which is part of the Greater Tokyo Area.

Dialing Formats and Caller Instructions

For local callers within Japan, the dialing format for numbers in the 464 area code is 0464-XX-XXXX (when dialing from outside the 046/464 overlay region) or 0464-XX-XXXX (when dialing from within the overlay region, the leading 0 is retained). However, due to the overlay, calls between the 046 and 464 codes are treated as local calls and require 10-digit dialing. For example, a call from a 046 number to a 464 number would be dialed as 0464-XX-XXXX.

For international callers, the format is +81 464-XX-XXXX (drop the leading 0). For instance, to call a business in Atsugi from abroad, you would dial +81 464-XX-XXXX. It is important to note that the subscriber number length is typically 8 digits, but some legacy numbers may have fewer digits; however, with the overlay, all numbers are standardized to 10 digits for local dialing.

Overlay Considerations and Number Portability

The introduction of the 464 overlay was necessary to meet the growing demand for new telephone numbers in the region without requiring existing subscribers to change their numbers. This overlay also facilitates number portability, allowing customers to switch between different service providers while retaining their existing numbers. For callers, this means that the area code does not necessarily indicate the physical location of the caller or the service provider; it is purely a routing identifier.

When placing calls from outside Japan, it is essential to use the correct country code (+81) and to omit the leading zero of the area code. For example, a call to a number in Atsugi would be dialed as +81 464-XX-XXXX. This format is consistent with ITU-T E.164 international numbering standards.