The My Number Card , officially Individual Number Card , is an identity document issued to citizens of Japan and foreign residents which contains a unique 12-digit Individual Number that serves as a national identification number in Japan. Unlike similar-looking identity cards in Europe, the My Number Card can be issued to both Japanese citizens and foreign residents, and is not proof of nationality. The My Number Card is used in Japan to streamline administrative purposes like filing taxes and social security, and it is also utilized to provide disaster response to those in need. It is the de facto Japanese equivalent to a U.S. Social Security Number.