When signing with MitID, you often reach a point where you need to enter your CPR number. After that, you're asked whether the CPR number should be remembered for a year. If you agree, MitID stores your CPR number within Unioo for a year. This means you won’t have to enter it again when signing with MitID over the next year.

It's often unnecessary, as most people won’t need to sign anything in Unioo within the next year. However, it doesn’t hurt to check the box.