You will first receive an overdue reminder for the book.

The 1st and 2nd overdue reminder is sent by e-mail. Please check that the library has your correct e-mail address.
 
The 3rd overdue reminder will be sent to you by mail. 
 
After some time you'll receive a notification of overdue claim.  At the same time, the case will be sent to NSSS' finance section, which is responsible for collecting the overdue claim. You will receive an invoice from the finance section.