Privacy and Freedom

The Japanese My Number System

Abstract

Since the 1970s, Japan has seen multiple attempts to introduce a nationwide personal ID system. One such initiative, a 1999 reform of the Basic Resident Registration Act (住民基本台帳法 Jūmin kihon daichō-hō), designed a network that would share information among various administrative agencies (the Resident Network System) and included a type of ID card. In 2002, shortly after the system was launched, it became the target of constitutional litigation that ultimately reached the Supreme Court.
In 2013, the Japanese National Diet passed a new national identification system known as the My Number System (マイナンバー制度 mainanbā seido) or Personal Number (個人番号 kojin bangō), which expands on the Resident Network System and seeks to include more information and enable extended use across multiple government services. Like the previous attempt, the new system was met with opposition and soon became the target of legal challenges. Finally, in 2023, the Supreme Court upheld the constitutionality of the My Number System. But regardless of the Supreme Court’s ruling, citizens have yet to accept the new system, to the point that the government has offered rewards and other incentives to encourage citizens to obtain the card. While there is evidence that these incentives have improved issuance rates, the use of the My Number Card remains relatively low.
The debate surrounding the My Number System illustrates that national identification systems are a two-pronged issue. One aspect concerns constitutional and legal protections, including universally recognized rights such as privacy and the right to self-determination, but also more recent information society rights associated with smart technologies. The other aspect focuses on the relationship between the government and citizens in terms of the implementation of a national identification system. Issues such as government goals are not necessarily aligned with the individual incentives that would improve trust in the system, particularly in the context of mixed signals and shifting goalposts.