What does BankID do with the information?

The legitimization is a real time operation where it is validated that you are the one you say you are. If the verification is successful a document will be transferred to the bank or end user that have asked for your legitimization. If the identification is unsuccessful, all gathered personal data are deleted. Furthermore, the company asking for your legitimization will be noted of the unsuccessful attempt. The company will inform you of the next step in the process. 

BankID does not store any information during the process that can be traced back to you personally.