Overview of Japan's Phone Number System
Japan's phone numbers are centrally managed by the Ministry of Internal Affairs and Communications (MIC) under Article 50 of the Telecommunications Business Act. Landline numbers are 10 digits including the area code, while mobile numbers are 11 digits. By examining the first few digits, you can determine whether a number belongs to a landline, mobile phone, toll-free line, or IP phone. Understanding this system helps you quickly assess the nature of incoming calls from unknown numbers.
The numbering system is divided into four main categories: landlines, mobile phones, IP phones, and special numbers. The MIC's Telecommunications Numbering Plan assigns number bands by purpose, with specific carriers and usage conditions defined for each band. Below, we explain the structure and practical points of each category.
Landline Number Structure
Area Code, Local Exchange Number, and Subscriber Number
Landline numbers consist of three elements: area code + local exchange number + subscriber number. Area codes range from 2 to 5 digits depending on the number of telephone subscribers in the region. Tokyo (03) and Osaka (06) have 2-digit codes, Yokohama (045) and Nagoya (052) have 3-digit codes, and Musashino (0422) has a 4-digit code. Shorter area codes mean longer local exchange numbers, always totaling exactly 10 digits.
Identifying Regions by Area Code
The digit following the leading 0 indicates the general region: 01 for Hokkaido, 02 for Tohoku/North Kanto plus Niigata and Nagano, 03 for Tokyo's 23 wards, 04 for the Tama area of Tokyo, Chiba, Saitama and Kanagawa, 05 for Chubu/Tokai plus Yamanashi, 06 for Osaka City, 07 for Kinki, 08 for Chugoku/Shikoku, and 09 for Kyushu/Okinawa. The mapping between area codes and numbering zones is set out in the appended tables of the MIC Telecommunications Numbering Plan. See How to Look Up Area Codes and Identify Regions for details.
Landline Digit Patterns
- 2-digit area codes: 03 (Tokyo 23 wards), 06 (Osaka City) and other major cities. 4-digit local exchange + 4-digit subscriber number
- 3-digit area codes: 011 (Sapporo), 045 (Yokohama), 052 (Nagoya), etc. 3-digit local exchange + 4-digit subscriber number
- 4-digit area codes: 0422 (Musashino), 0798 (Nishinomiya), etc. 2-digit local exchange + 4-digit subscriber number
- 5-digit area codes: 04992 (Hachijojima) and other remote islands. 1-digit local exchange + 4-digit subscriber number
Mobile Phone Number Structure
Mobile phone numbers are 11 digits starting with 090, 080, or 070. Unlike landlines, they are not tied to any geographic region and are used nationwide. Since the introduction of MNP (number portability) in 2006, it is no longer possible to identify the carrier from the first three digits.
History of Each Number Band
The 090 band is the oldest of the three, and has been used in its current form since the 1999 transition to 11-digit numbers. As subscribers grew, the 080 band was added in 2002, and in 2013 the 070 band - previously reserved for PHS - was opened to mobile phones as well. As of 2026, roughly 265 million numbers across the 090, 080, and 070 bands have been designated to carriers, and every block in the 090 and 080 bands is already taken (MIC, Telecommunications Number Designation Status).
IP Phone Number System
IP phones (VoIP) use 11-digit numbers starting with 050. These services carry voice calls over the internet and are typically cheaper than traditional landlines. However, 050 numbers cannot place emergency calls (110/119), so make sure you have another way to reach emergency services before signing up.
IP phone services such as NTT's Hikari Denwa (fiber optic phone) offer numbers with traditional area codes (0AB-J numbers). These are technically IP phones but use the same numbering system as conventional landlines, providing greater social credibility. The PSTN to IP network migration was completed in January 2025, switching the landline network over to IP.
Special Number Bands
- 050: IP phone. Internet-based telephone service
- 0120: Free Dial. Toll-free number where the receiver pays call charges
- 0800: Free Call. A toll-free service similar to 0120
- 0570: Navi Dial. Nationwide flat-rate number where the caller pays
- 0990: Premium-rate information service number. Information fees charged on top of call charges
- 110, 119, 118: Emergency numbers. For police, fire/ambulance, and Japan Coast Guard
Expanding the Number Supply
Designation has advanced band by band, and the 090 and 080 bands have no capacity left. In December 2024 the MIC amended the Telecommunications Numbering Plan to add 11-digit numbers beginning with 060 (060-1 through 060-9) for mobile phones, making roughly 90 million more numbers available; commercial service had not started as of August 2026. Data communication for devices uses the 020 band, where the plan specifies a 14-digit format beginning with 0200.
Japan's Phone Numbers in an International Context
Japan's phone number system complies with the E.164 recommendation established by the ITU. E.164 defines the international format for phone numbers, uniquely identifying any number worldwide through a combination of country code + national number. Japan's country code is +81, and converting to international format requires dropping the leading 0 (trunk prefix) and replacing it with +81. See Guide to Japan's Country Code +81 for details.
For example, a Tokyo landline number 03-1234-5678 becomes +81-3-1234-5678 in international format. A mobile number 090-1234-5678 becomes +81-90-1234-5678. Understanding this conversion rule is essential when communicating internationally or registering numbers with global services.
Detailed Number Band Classification
Japanese phone numbers are clearly classified by their leading digits. Knowing this classification lets you instantly identify the type of incoming call.
0AB-J Numbers (Landlines)
Landline numbers beginning with area codes. The digit after 0 (1-9) indicates the general region. The subscriber number is always 4 digits, with the area code and local exchange number totaling 6 digits.
020 Numbers (M2M Communications)
A number band for device data communication (M2M). The MIC Telecommunications Numbering Plan specifies a 14-digit format beginning with 0200, and numbers in the older 11-digit format (020 plus one letter) are being migrated to it. Typical users are vending machines, smart meters, and vehicle telematics devices.
0AB0 Numbers (Special Services)
Number bands assigned by function, such as 0120 (Free Dial), 0570 (Navi Dial), and 0800 (Free Call). The MIC numbering plan calls these "supplementary service telephone numbers" and defines each band by function: toll-free service (0120, 0800), unified number service (0570), and information-fee collection (0990). These numbers are not tied to any region and are used nationwide.
Phone Numbers and Personal Information
Phone numbers may qualify as "personal information" under Japan's Act on the Protection of Personal Information. Since a phone number combined with a name or address can identify an individual, businesses collecting customer phone numbers must clearly state the purpose of use and implement appropriate security measures.
Additionally, if your phone number is registered with social media or web services, there is a risk of being identified through reverse lookups. For those who value privacy, consider using different numbers for different services or using a 050 IP phone number as a secondary number. It is also wise to familiarize yourself with what to do if your phone number is exposed in a data breach.
Numbering Plan Management and the Role of the MIC
Japan's phone numbering plan is developed and managed by the Ministry of Internal Affairs and Communications (MIC). Under the Telecommunications Business Act, numbers are designated to carriers in blocks whose size differs by band: 100,000 numbers per block for mobile numbers, and 10,000 for 050 and 0800 numbers. Allocation status is published on the MIC's "Telecommunications Number Designation Status" page, where you can check which number bands are assigned to which carriers. Carriers that receive a designation report their number usage to the MIC once a year under the Telecommunications Business Reporting Rules.
Revisions to the numbering plan take the form of MIC amendments to the plan itself; the December 2024 addition of the 060 band and the shift to a 14-digit format in the 020 band are two examples. A systematic understanding of the numbering system serves as a foundation for choosing communication services and dealing with unknown numbers.