Interlibrary loan

Interlibrary loan (abbreviated ILL, and sometimes called interloan, document delivery, or document supply etc.) is a service whereby a user of one library can borrow books, videos, DVDs, sound recordings, microfilms, or receive photocopies of articles in magazines that are owned by another library. Sometimes for a small fee, or possibly for no cost, a library that has the item will loan or copy it, and the item is transported to the requestor's library to be checked out or used only within the library.

Generally, the term document delivery means more specifically the supply of journal articles and other copies on a personalized basis, with the library charging the user or his academic department for the fees that are often involved.

Without interlibrary loans, if a library patron found an item they wanted, he would have to travel to that library, and apply for a local library card if eligible, or present a reciprocal card in order to borrow the item. By taking advantage of interlibrary loan, in comparison, the library staff can search large numbers of libraries at once, transport the item from several miles to thousands of miles away, and allow a patron to borrow the item using his or her local library card.

How interlibrary loan works

Interlibrary loan, or resource sharing, generally has two operations: borrowing and lending.

  • A borrowing library sends a lending library a request to borrow, photocopy, or scan materials for use by their requestor.
  • A lending library fills the request by sending materials to the borrowing libraries.
  • Libraries that borrow generally also lend.

Commercial document delivery services can borrow on behalf of anyone willing to purchase the information.

Interlibrary loan and resource sharing have a variety of systems and workflow, often based on the scale of service, regional networks, and library systems. Processes are automated by computer systems such as VDX based on ISO ILL standards 10161 and 10160.

Loans requests between branch libraries in the same system may be filled in a brief amount of time, while loan requests between library systems may take weeks or more to be delivered. If an item is rare or difficult to find, this may be the easiest way to gain access to it. However, if an item is rare or difficult to find, interlibrary loan does not guarantee that the lending library will send the item through a local library. Some collections and volumes may be non-circulating. Urgent requests are placed if the item is needed urgently. These requests should be prioritized and supplied quickly. Books may be posted by courier and photocopies may be faxed or scanned and sent electronically. Additional fees may be charged for urgent service. Public libraries do not generally offer urgent service.


Traditionally, library users discovered potentially useful titles from book advertisements, through word-of-mouth from a friend or an authority on the subject, consulting the bibliographies found at the back of books or published as a separate book, or a printed union catalog of all the books in a group of libraries such as NUCMC. Requests were filled out on a standardized form and sent by postal mail to a library that allegedly owned a copy. This procedure is still used by libraries that are not members of an electronic interlibrary loan network. Since the mid-1980s, searching for books located at other libraries has become easier, as many libraries have allowed library users to search their online catalogs at the library or over the Internet.

Resource sharing networks

Libraries have formed voluntary associations with each other to provide an online union catalog of all the items held by all member libraries. Whenever a library adds a new item to its catalog, a copy of the record is sent to update the union list. This allows libraries to quickly find out what other libraries hold an item, and software can facilitate the requesting and supplying of interlibrary loans. In the U.S., OCLC (Online Computer Library Center) is usually used by public and academic libraries, and RLIN (Research Libraries Information Network) is used primarily by academic libraries, although some libraries are members of both. Australia and New Zealand use Libraries Australia and Te Puna respectively, the national bibliographic networks of those countries.

Libraries that do not belong to a network can participate in interlibrary loan by making the arrangements by postal mail, fax, email or phone. Requests placed in one of these ways are referred to as manual requests.

Libraries may also have reciprocal arrangements with each other in order to supply loans and copies for free.

Useful information for interlibrary loan users

  • Interlibrary loan policies vary from country to country and library to library.
  • New release or in high demand titles (such as Harry Potter or The Da Vinci Code) may not always circulate through ILL because libraries may lend them to their own patrons first. Please consider putting a hold on the new release title you want at your own library before having it go unfilled weeks or months later. Similar difficulties apply to current textbooks.
  • The patron requesting the item does not need to locate a library owning a particular title. Most libraries will do this for their patrons when they place the request. The OCLC First Search WorldCat Database is the best place to look for items not held in your own library. Many libraries have an online "order form" to use to obtain the items, although some libraries still use print order forms.
  • If an item is not available from libraries in your own country, it might be possible to get it from another country, although this may be more difficult. Neighboring countries should be tapped first for faster turnaround time. Insurance and shipping charges may be an issue regarding loans from other countries. Check with the interlibrary loan staff regarding questions on these charges and whether any costs will be passed on to you.

  • A rare book may be hard to obtain, but some libraries are willing to consider lending books that may be considered rare in others. more than one Interlibrary loan department will usually try to obtain most requested items. Rare items are almost always restricted to use in the borrowing library, however. The alternatives are to check for the possibility of reprints, check for the availability of text in free ebook repositories--and if necessary, paying for a microfilm copy.
  • Journals are not usually lent; rather, a photocopy is made of the article requested. The policies are different in different countries, but usually a copy can be obtained. It may be necessary to obtain it from a source that charges a copyright fee, which may be anywhere from $3 to $35 and sometime higher. Policies vary about whether the patron is charged for this.

Journals dealing with interlibrary loan

The leading journals in the field are:

  • Journal of Interlibrary Loan, Document Delivery and Electronic Reserve, Haworth Press. (Earlier title: Journal of Interlibrary Loan, Document Delivery & Information Supply).
  • Interlending and Document Supply
  • Journal of Access Services

External links

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