The National Library Act 2003 states that “Every publisher of a book or document in Uganda, at his/her cost to deposit three copies of the book or document or one copy of the video gram or film and ten copies in the case of any government departments with the National Library." This is what is referred to as legal deposit.The main goal of legal deposits is to preserve Uganda's Documented Heritage. 

One of the functions of National Library of Uganda, is to promote the habit and culture of reading among Ugandans through reading campaigns and book exhibitions. In light of this,  the National Library of Uganda endeavors to instill and promote a culture of reading among Ugandans, through organizing children reading tents very year, where children come and engage in various activities like reading (physical books and e-readers), drawing, spelling, story writing competitions, and book-making activities.

The National Library of Uganda Act, 2003 gives the National Library of Uganda the mandate to allocate International Standard Book Numbers and International Standard Serial Numbers to Authors and Publishers. It is always the Publisher or Author of a book who should apply for the ISBN. The Publisher in this case being a group, organization, company, or individual responsible for initiating the production of a publication.

Every year, National Library of Uganda receives significant donations of books from Book Aid International. The books are processed and distributed evenly, to public and community libraries throughout Uganda.