This is not a compulsory field.

The national registry number is only requested so that we can link your Liantis account to you with certainty if you experience problems with itsme® or eID, or to further assist you as a member of the social insurance fund.
We do not further process or pass on the national register number. The data are stored and available to you for up to 120 days after your query is dealt with, in order to be able to follow up the history of your query.

You can find more information on our privacy statement.