Yamato Transport, one of Japan's largest parcel delivery companies, confirmed on Friday that about 5.31 million customer data records, including names and addresses, were leaked following unauthorized access to its payment service system.
According to the company's notice, the affected data was held in the payment processing system and was accessed without authorization. The disclosure came after the firm carried out checks and verified the scope of the impact.
Yamato Transport said it is working with authorities to investigate the cause and to take measures to prevent further risks. The company also said it will continue to update customers on the situation and on its response measures.
It is one of the largest customer data leaks involving a delivery company in Japan in recent times.
