Area Code 2586 – Nagaoka, Niigata

Overview of Area Code 2586

Area code 2586 is a geographic National Destination Code (NDC) within the Japanese numbering plan, assigned to the city of Nagaoka in Niigata Prefecture. It covers the central and eastern parts of Nagaoka, including districts such as Nagaoka Station area, Ojiya, and surrounding communities. The code is part of the larger Niigata numbering area, which uses the prefix 0258 for Nagaoka and its vicinity. The 2586 prefix is specifically used for landline (fixed-line) telephone services in this region.

Dialing Formats

When calling a number in Nagaoka from within Japan, you must dial the trunk prefix 0, followed by the area code 2586 and the subscriber number. The complete domestic format is 0-2586-XX-XXXX. For international callers, the country code for Japan is +81, and the leading 0 is omitted. Thus, the international format becomes +81-2586-XX-XXXX. For example, a local Nagaoka number might be 0-2586-12-3456 domestically, and +81-2586-12-3456 from abroad.

Geographic Coverage and Administration

Nagaoka is a major city in Niigata Prefecture, located on the Sea of Japan coast. The 2586 area code serves the city’s central business district, residential neighborhoods, and industrial zones. It is administered by the Japanese Ministry of Internal Affairs and Communications (MIC) and operated by Nippon Telegraph and Telephone (NTT) East, which is the incumbent local exchange carrier for the region. As a geographic code, it is tied to a physical location, and numbers are typically assigned to fixed-line services, including residential, business, and public telephones.

Overlays and Numbering

Currently, there are no overlay codes in the Nagaoka area; the 2586 code is the sole NDC for this region. Subscriber numbers are typically 4 to 6 digits long, making the total national significant number (NSN) length 10 digits when including the area code. This structure complies with the ITU-T E.164 recommendation for Japan, where the maximum NSN length is 11 digits (including the leading 0 for domestic calls).

Caller Instructions

For local callers within the same area code, it is possible to dial just the subscriber number without the area code, depending on the local dialing plan. However, for calls from other regions in Japan, you must dial the full domestic number starting with 0. For international callers, always replace the leading 0 with the +81 country code. Be aware that some VoIP services may require different dialing procedures, so it is advisable to check with your service provider.