Area Code 2678 – Saku, Nagano

Overview of Area Code 2678

Area code 2678 is a geographic National Destination Code (NDC) assigned to the city of Saku in Nagano Prefecture, Japan. It is part of the Japanese telephone numbering plan under ITU-T E.164, where the country calling code is +81. The code covers the administrative area of Saku City and its surrounding regions, including former towns and villages such as Usuda, Maki, and Nakagomi, which were merged into the expanded city. The service area is located in the eastern part of Nagano Prefecture, near the border with Gunma Prefecture, and is known for its scenic highlands and agricultural production.

Dialing Formats

For callers within Japan, the national trunk prefix 0 is used before the area code. The local number format is 0-2678-XX-XXXX, where the total number of digits after the trunk prefix is 10 (including the area code). For example, a local number might be 0-2678-56-7890. When dialing from abroad, callers must use the international prefix (e.g., + or 011 in North America), followed by Japan's country code 81, and then the area code without the leading zero. Thus, the same number would be dialed as +81-2678-56-7890. It is important to note that the area code is not separated by a space when dialing internationally; the format is simply +81 2678 56 7890.

Geographic Coverage and Administration

Saku City is the administrative center for this area code. The region is part of the Kanto-Koshinetsu area and is served by NTT East (Nippon Telegraph and Telephone East). The city is home to the Saku City Office and various public facilities. The area code 2678 is one of several NDCs in Nagano Prefecture, which also includes codes like 026 (Nagano City) and 0265 (Matsumoto). The allocation of this code follows the traditional geographic numbering plan, where each NDC corresponds to a specific telephone exchange area. Over the years, as the population and business needs have evolved, no overlay codes have been introduced for Saku; the 10-digit dialing plan (including the area code) remains standard for all calls within Japan.

Caller Instructions

For local callers within the Saku area, it is possible to dial the 6-digit subscriber number without the area code, but this practice is becoming less common as Japan moves toward unified dialing. For long-distance calls within Japan, dial 0 followed by the area code and the subscriber number. For international callers, always drop the leading 0 and use the country code +81. Be mindful of time zone differences; Japan Standard Time (JST, UTC+9) has no daylight saving time. When calling from a mobile phone, the same rules apply, but international roaming charges may apply if you are using a non-Japanese SIM card.

Practical Examples

• Local call (within Saku): 56-7890 (if supported) or 0-2678-56-7890.
• National call (from Tokyo): 0-2678-56-7890.
• International call (from USA): +81-2678-56-7890.