From 8:30pm on 31 January 2024 you will no longer be able to unlock smartcards in the old Care Identity Service application.
If you unlock smartcards, from 8:30 pm on 31 January 2024 you must use either:
self-service smartcard unlock, to unlock your own smartcard
Care Identity Management, to unlock other people’s smartcards as a Registration Authority or local smartcard administrator
You can read the full details in this announcement.