What city is area code +81 2583 associated with?

The +81 2583 area code is associated with the Nagaoka region in Niigata Prefecture, specifically covering the former Tochio and Ojiya areas, which are now part of Nagaoka City.

How do I dial a number in the 2583 area code from outside Japan?

Dial your country's international access code (e.g., 011 from the US or 00 from most European countries), then Japan's country code 81, followed by the area code 258 (without the leading zero) and the local number. For example, +81 258 3X XXXX.

Is +81 2583 a mobile or landline prefix?

It is a geographic landline prefix. Mobile numbers in Japan begin with 070, 080, or 090, not with 2583.

What is the local dialing format within the Nagaoka area?

Within the same area code region, you can dial the local number directly, which is typically 7 digits, starting with 3X-XXXX. For example, 3X-XXXX. If you are outside the area but still in Japan, you must dial 0258-3X-XXXX.

Are there any overlays or multiple area codes for Nagaoka?

No, Nagaoka uses a single area code 0258. There is no overlay code. The 2583 is a sub-code within that area code, used for specific exchanges.

Area Code 2583 (Japan) - Prefix Details & Exchanges

Geographic Overview

The +81 2583 area code is a geographic National Destination Code (NDC) assigned to the Nagaoka region in Niigata Prefecture, Japan. Specifically, it serves the Tochio and Ojiya areas, which are administratively part of Nagaoka City. This code is part of the larger Nagaoka numbering plan area (NPA) that historically used the 0258 prefix. The 2583 code is used for fixed-line PSTN services, and it is not assigned to mobile networks.

Dialing Formats

For local callers within the Nagaoka area code region, the number is dialed as 0258-3X-XXXX (where X represents digits). When calling from another area code within Japan, the full national number must be dialed: 0258-3X-XXXX, preceded by the trunk prefix 0. For international callers, the number is dialed as +81 258-3X-XXXX, omitting the leading zero of the NDC.

Geographic Coverage and Administration

The 2583 area code covers the former Tochio and Ojiya cities, which merged into Nagaoka City in 2005 and 2010, respectively. Nagaoka is the second-largest city in Niigata Prefecture, known for its industrial base, including machinery and metalworking. The area is served by Nippon Telegraph and Telephone East (NTT East) as the primary local exchange carrier.

Numbering and Overlay Considerations

Japan's numbering plan follows ITU-T E.164 recommendations. The Nagaoka area code 0258 is a closed numbering plan, meaning that local numbers are typically 7 digits long (excluding the area code). There is no overlay code for this region; the 0258 code is unique to the Nagaoka area. However, within the 0258 code, sub-codes like 2583 are used to identify specific exchanges or districts.

Caller Instructions

For callers within Japan: To call a number in the 2583 area from another region, dial 0-258-3X-XXXX. For callers outside Japan: Dial your country's international access code (e.g., 011 from the US), then 81 (Japan's country code), followed by 258-3X-XXXX. Do not include the leading 0 of the area code when dialing internationally.

Regulatory and Technical Notes

As with all Japanese geographic numbers, the 2583 code is regulated by the Ministry of Internal Affairs and Communications (MIC). Number portability is available for fixed-line services, allowing subscribers to retain their numbers when switching carriers within the same geographic area. However, the geographic significance of the code remains, and it is not used for nomadic VoIP services.

Area Code 2583 – Nagaoka, Niigata

📍 Geographic Location of Nagaoka, Niigata