Area Code 1556 – Obihiro, Hokkaido

Overview of Area Code 1556

Area code 1556 is a geographic National Destination Code (NDC) assigned to the city of Obihiro and its surrounding areas in the Tokachi subprefecture of Hokkaido, Japan. This code is part of the Japanese telephone numbering plan, which adheres to ITU-T E.164 recommendations. The region served by 1556 includes Obihiro City, as well as nearby towns such as Otofuke, Makubetsu, and portions of Ikeda and Honbetsu. The area is known for its agricultural production and is a major commercial hub in eastern Hokkaido.

Dialing Formats

When calling a landline in Obihiro from within Japan, the trunk prefix 0 is dialed first, followed by the area code 1556 (without the leading zero) and the subscriber number. For example, to call a number in Obihiro from Tokyo, you would dial: 01556-XXXXXX. Internationally, callers must use Japan's country code +81, drop the leading zero, and dial: +81 1556-XXXXXX. Subscriber numbers in this area typically consist of 5 to 6 digits, making the total national significant number (NSN) length 10 digits when including the area code.

Geographic Coverage and Administration

The 1556 area code is administered by NTT East, the regional telecommunications carrier. It covers the Tokachi Plain, one of Japan's most productive agricultural regions. Key cities and towns within this code include Obihiro, the largest city in the area, and the neighboring town of Otofuke, which hosts the Obihiro Airport. The region is also home to the Tokachi Millennium Forest and several hot spring resorts, attracting both domestic and international visitors.

Calling Instructions

Local callers: When dialing within the same area code, you may omit the area code and dial only the subscriber number. However, if you are using a mobile phone or a VoIP service, it is recommended to always include the area code to avoid misrouting.

Domestic long-distance callers: Dial the trunk prefix 0, then the area code 1556, followed by the subscriber number. For example: 01556-XXXXXX.

International callers: Dial your country's international access code (e.g., 011 from the US), then Japan's country code 81, then the area code 1556 (without the leading zero), and the subscriber number. For example: 011-81-1556-XXXXXX from the US.

Overlay and Numbering Considerations

As of the latest ITU-T operational bulletin, there is no overlay code for 1556. The area code remains a standalone geographic code, and number portability is available for fixed-line services within Japan, allowing subscribers to retain their numbers when switching carriers. However, geographic numbers are generally tied to the physical location, and moving outside the area may require a number change.