How long can I use my Zengaku ID?

For the moment, until all regular students hold student IDs where their NU IDs are printed (Apr. 2013), we are planning to keep the Zengaku ID available. The Zengaku ID will be available as long as there are services that have difficulties shifting from the Zengaku ID to the NU ID. We will gradually promote providing all services using only the NU ID.