Area Code 1378 – Imakane, Hokkaido

Overview of Area Code 1378

Area code 1378 is a geographic numbering plan area within the Japanese telecommunications network, specifically designated for the town of Imakane in the Hiyama Subprefecture of Hokkaido. This code is part of the national numbering plan administered by the Ministry of Internal Affairs and Communications (MIC) and follows the ITU-T E.164 international standard. The region is rural and sparsely populated, with the code serving the town's PSTN and VoIP subscribers.

Geographic Coverage and Administration

Imakane is located in the southwestern part of Hokkaido, bordered by the Setana River and the Sea of Japan to the west. The area code 1378 covers the town's administrative boundaries, including its central districts and surrounding agricultural communities. As a geographic code, it is tied to the physical location of the subscriber's line, although number portability allows users to retain their numbers when moving within the same service area.

Dialing Formats

For domestic calls within Japan, the full national number is dialed as 01378 followed by the subscriber's 5-digit local number, resulting in a total of 10 digits (including the leading '0'). For example, a local call to a business in Imakane would be dialed as 01378-5-XXXX (where '5' is a typical central office prefix). When calling from overseas, the international format is used: +81 1378 5 XXXX, omitting the leading '0' of the national prefix. Callers from other countries should replace the '+' with their international access code (e.g., '011' from the US, '00' from most European countries).

Overlay and Numbering Considerations

Currently, there is no overlay code for area 1378, meaning that local calls within Imakane do not require an area code. However, as part of Japan's numbering plan, the MIC has implemented number portability and VoIP integration, allowing subscribers to retain their numbers when switching providers. For mobile calls to Imakane, callers must include the area code even when dialing from a mobile phone, as mobile numbers are non-geographic and require the full national number.

Caller Instructions

For local callers within Imakane, dial the 5-digit subscriber number directly. For callers from other parts of Japan, dial 01378 followed by the subscriber number. For international callers, dial +81 1378 followed by the subscriber number, omitting the leading '0'. It is important to note that the area code is essential for routing calls correctly, especially in a country with a dense and complex numbering plan like Japan.