Federal law sets forth permissible purposes for credit reports. Such purposes include allowing the bank to review your credit report to ensure that you meet the terms of your accounts with the bank. It is also permissible in connection with a business transaction which you initiate or the establishment or maintenance of a credit transaction. Thus, there are several possible justifications for the bank to do so depending upon the type of accounts you maintain with the bank. Still, I would not hesitate to ask them why they did so. If it puts your mind at ease, it is my understanding (although I am not certain) that this type of inquiry is not detrimental to your credit score as are some other types of credit report pulls.