Library materials and information services provided by the National University Library (NUK) of Slovenia are accessible only to members. A library user can be any legal subject. A legal subject is anyone above fifteen years of age.

Members who are above eighteen years of age and are residents of Slovenia or regular students at one of the three Slovenian universities can take library materials out of the library on loan, while other members can use library materials only in the reading rooms.

Foreign citizens wishing to register or renew membership must present their passport and sign an agreement that they will observe the terms for borrowing materials from the library. They are also required to pay an annual fee according to the current price list and choose a password for use in security checks and extending the loan period for borrowed items.