Area Code 1555 – Obihiro, Hokkaido

Overview of Area Code 1555

Area code 1555 is a geographic National Destination Code (NDC) assigned to the city of Obihiro and its surrounding municipalities in the Tokachi subprefecture of Hokkaido, Japan. Under the ITU-T E.164 numbering plan, the full international dialing format for a fixed-line number in this region is +81 1555 XXXX, where the national significant number (NSN) is 10 digits in length (excluding the leading trunk prefix '0').

Geographic Coverage and Administrative Jurisdiction

The 1555 code covers Obihiro City, the commercial and administrative hub of the Tokachi region, as well as adjacent towns such as Otofuke, Makubetsu, and Ikeda. The area is served by NTT East (NTT Higashi-Nihon) as the primary local exchange carrier, with alternative carriers offering services via interconnection. The numbering area is defined by the Ministry of Internal Affairs and Communications (MIC) and is part of the Hokkaido telephone district.

Dialing Formats and Instructions

Local callers within the 1555 area can dial the 6-digit subscriber number (XXXXXX) directly, omitting the area code. For calls from other regions in Japan, dial the trunk prefix 0, followed by the area code and subscriber number: 0-1555-XXXXXX. International callers should dial their country's exit code (e.g., 011 from the US, 00 from most European countries), then Japan's country code 81, followed by the area code without the leading '0' and the subscriber number: +81 1555 XXXXXX.

Numbering and Overlay Considerations

As of 2025, there is no overlay code for the 1555 area; the 10-digit NSN format remains consistent. However, with the gradual migration of NTT East's fixed-line services to IP-based networks, some numbers may be provisioned over VoIP, but the geographic significance of the code is retained for routing and emergency services (110 for police, 119 for fire/ambulance). Callers should note that while the code is geographically tied to Obihiro, number portability allows subscribers to retain their numbers when moving within Japan, though the geographic association remains for regulatory purposes.

Practical Examples

• Local call: 123456 (within Obihiro)
• National call (from Tokyo): 0-1555-123456
• International call (from the US): 011-81-1555-123456
• International call (from the UK): 00-81-1555-123456

When dialing from a mobile phone in Japan, the same national format applies. For businesses, it is advisable to display numbers in international format (+81 1555 XXX XXX) to facilitate global contact.