Area Code 2855 – Oyama, Tochigi

Geographic Coverage and Administrative Jurisdiction

Area code 2855 is a geographic National Destination Code (NDC) assigned to the city of Oyama and its surrounding areas in Tochigi Prefecture, Japan. Specifically, it covers the western part of Tochigi Prefecture, including the city of Oyama, which is a major commercial and industrial hub. The code is administered under the Japanese Ministry of Internal Affairs and Communications (MIC) numbering plan, which follows ITU-T E.164 standards. The service area is part of the Kanto region, though it lies outside the immediate Tokyo metropolitan area.

Dialing Formats and Caller Instructions

For local callers within the same NDC area (i.e., when dialing from another number with the 0285 prefix), the area code is typically omitted, and only the 7-digit subscriber number is dialed. However, when calling from outside the 0285 area but still within Japan, the full national number must be dialed: 0285-XX-XXXX (where X represents the subscriber digits). For international callers, the format is +81 2855 XX-XXXX (or +81-285-XX-XXXX if the subscriber number is 7 digits, but note that the NDC is 4 digits: 2855). Always replace the leading zero with the country code +81 when calling from abroad.

Overlay and Numbering Considerations

As of the latest updates, there is no overlay code for the 0285 area; the 4-digit NDC remains unique to the Oyama region. Subscriber numbers are 7 digits long, making the total national significant number (NSN) 11 digits (including the leading zero). The numbering capacity is sufficient for the region's population, and no changes are currently planned.

Primary Cities and Coverage

Besides Oyama city, the 0285 area code also covers parts of Tochigi city (formerly known as Tochigi-shi) and the town of Mooka (though Mooka has its own code, 0285 is used for some areas). The region is known for its agricultural production and manufacturing, particularly in the automotive and electronics sectors. Major landmarks include the Oyama Castle ruins and the Omoi River.

Practical Guidance for Callers

For local callers within Japan, simply dial 0285-XX-XXXX. For international callers, dial +81 2855 XX-XXXX (or +81 285 XX-XXXX if you drop the last digit of the NDC? Actually, the NDC is 2855, so after +81, you dial 2855 followed by the 7-digit subscriber number, e.g., +81 2855 123 4567). Ensure you include the correct number of digits: the subscriber number is 7 digits, so the full international number should be +81 2855 123 4567 (total 13 digits including country code). When calling from a mobile phone, the same rules apply. For VoIP services, the same numbering format is used.