Interlibrary Loan

Interlibrary loan (abbreviated ILL, and sometimes called interloan, document delivery, or document supply) is a service whereby a user of one library can borrow books or receive photocopies of documents that are owned by another library. The user makes a request with their local library, which, acting as an intermediary, identifies owners of the desired item, places the request, receives the item, makes it available to the user, and arranges for its return. The lending library usually sets the due date and overdue fees of the material borrowed. Although books and journal articles are the most frequently requested items, some libraries will lend audio recordings, video recordings, maps, sheet music, and microforms of all kinds. In many cases, nominal fees accompany interlibrary loan services.

The term document delivery may also be used for a related service, namely the supply of journal articles and other copies on a personalized basis, whether these come from other libraries or direct from publishers. The end user is usually responsible for any fees, such as costs for postage or photocopying. Commercial document delivery services will borrow on behalf of any customer willing to pay their rates.