User ID
You can no longer use your CPR number as user ID. It strenghtens of the allround security that the user ID you select is unique and not something that can be identified through access to CPR numbers.
You should create a user ID, which is difficult for others do guess but still easy for you to remember (e.g. by combining numbers, letters and special characters). Don't ever share your user ID with any other person - that is apart from MitID support, if you contact them yourself. You can always change your user ID on MitID.dk.
Activation before use
Before you can use either MitID app, MitID code display or MitID chip it must be associated with you. This means that criminals cannot steal your MitID code display from your mailbox and use it on your behalf. This is also applicable to the MitID app, which must be activated using two independent codes that you receive via two independent channels.
Notifications about important incidents
You will be notified via the MitID app, SMS or email, if an important event occur. This could be if the MitID app is activated on a new unit, or if a code display is activated. You can choose to be notitied everytime your personal MitID is used. This way you will be notified if MitID events demand your actions.
When you get MitID, you must choose, which type of notifications, you want to receive and through which channel. You can always change it later on MitID.dk.
It is recommended that you choose two channels to be notified through. If MitID encounter errors when notifying through one channel, then you can get notified through another.
Text that enables you to act
MitID will tell you what to do through text (e.g. "Log 't on"). If the text doesn't match your intentions, or if you haven't initiated the transaction, do not approve using MitID.
Read additional material here (PDF)