A landline phone is a telephone connected to a line installed at a fixed location such as a home or office. Its structure of area code + local exchange code + subscriber number allows the installation region to be identified from the number itself - its most distinctive feature. The history of landline phones in Japan dates back to 1890, when telephone exchange service began between Tokyo and Yokohama, and they have served as the foundation of communications infrastructure for over 130 years.
Landline subscriptions have been declining steadily with the spread of mobile phones. From a peak of approximately 63 million lines in 1997, the number fell to about 14 million by the end of fiscal year 2023. The decline is especially pronounced among younger households, with landline ownership rates below 10% for those in their 30s and younger. Meanwhile, over 80% of households headed by someone 60 or older still have a landline, creating a significant generational gap.
Despite declining subscriptions, landlines still play important roles. In business, having a landline number starting with 03 or 06 enhances corporate credibility. Landline numbers may be required for opening bank accounts or registering a corporation. When making emergency calls (110/119), landlines automatically transmit address information tied to the phone number, enabling more precise location identification than mobile GPS. Additionally, integration with internet lines through Hikari Denwa (fiber-optic phone) has made it possible to maintain a landline for as little as 550 yen per month.
NTT completed the migration from PSTN (Public Switched Telephone Network) to an IP-based network in January 2024. While the user experience and phone numbers remain essentially unchanged, the underlying technology has shifted from analog circuit-switching to digital packet-switching. This migration ended ISDN data communication services (INS Net), but voice calls continue to be available. See Phone Number Structure for the numbering system and How to Look Up Area Codes for identifying regions.