No need to issue a card. They could build up the information required for all the data fields over time, and the obligation to inform them of changes in circumstances for life, address etc, would be imposed at a stroke.
The trigger event for the notification obligations under the Act appears to be an application to be registered. Though there is provision for information to be entered on the NIR by the Secretary of State without an application, he has no obligation to inform you that such an entry is being made, and you do not therefore seem to be registered in quite the same way. It is one of the stranger bits of the Act.