Around 7,300 cases involving My Number national identification cards linked to health insurance data have been found to have contained erroneously registered information, the health ministry has said.
Such errors have led to five cases in which users' medical information has been exposed to others between October 2021 and November 2022, a health ministry survey showed Friday.
The incorrect registrations have since been corrected, and relevant organizations, such as health insurance associations, have been requested to ensure they do not occur again, the Ministry of Health, Labor and Welfare said.
It is believed that the health insurance associations had incorrectly registered My Number card information, enabling users to inadvertently access other people's data, such as prescription medication and medical expenses, on the system's portal site.
The ministry said it is coordinating with the relevant organizations to employ measures, such as checking names and birth dates, to ensure no errors are made during registration.
Separately, the ministry confirmed on Friday 14 cases across different cities of the wrong residence certificates being issued to people using the My Number card's function to print documents at convenience stores, including two in Tokyo's Adachi Ward and 10 in Yokohama.