ISO 18626 Interlibrary Loan Transactions

ISO TC46/SC4/WG14 Interlibrary Loan Transactions



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Last update: 21 July 2016


News and information about implementation of the new standard for ILL:

- ISO 18626 Information and documentation - Interlibrary Loan Transactions



ISO 18626 Information and documentation - Interlibrary Loan Transactions will at first supplement and eventually succeed ISO 10160, ISO 10161-1 and ISO 10161-2. Unlike its predecessor, ISO 18626 is well suited to the modern, Web-based technological environment which is based on XML and Web services. Another important difference between the two standards is that while the old standard is based on a 1980s model of ILL transactions, its successor is based on and supports much simpler exchange of transactions.


The standard includes three simple messages: a request, a supplying library message and a requesting library message and confirmations messages for this. The protocol is stateless, which means that there will be no need to maintain the interconnected state tables in the client and server applications (and the connections to the state tables in applications behind them). It is expected that the new ILL protocol will be much easier to implement than the old one, while still retaining the essential functionality of its predecessor.


ISO 18626 is the first part of a more general strategic initiative to standardize resource sharing in ISO/TC46/SC4 Technical Interoperability.



Open Codes

The list of open codes is prescribed in the standard, but will be continuous extended.



The guidelines and use cases is prescribed in the standard, but will be continuous extended.



XML Schema

The actual XML schema for ISO 18626.











To purchase the standard:

Contact your national ISO member body or use

the ISO store online:




ISO Members:







Convener Leif Andresen

ISO TC46/SC4/SC14 Interlibrary Loan Transactions


Editors of ISO 18626: Leif Andresen (The Royal Library, Denmark), Clare Mackeigan (Relais International), and Ed Davidson (OCLC).


Members WG14


For regular updates regarding the ISO 18626 standard and implementations subscribe to the newsletter.



21 July 2016

On Aug 17, 2016 join us at OCLC to learn more about ISO 18626.


More details are available in the

ISO 18626 Newsletter #3


14 March 2016

ISO 18626 Newsletter #2


14 March 2016

Proposals for improvement of ISO 18626 - As part of the continuous review process for this standard, implementers and potential implementers are invited to submit suggestions for improvement to ISO 18626. The ISO 18626 editor group is opening a three month long window for proposals. For example: it has been recommended that a new Request Type be added to handle requests from book clubs. As well as a new RequestType = MultipleReservation, a StartDate and EndDate would be added to the Request message. Please send your proposals along with any other feedback or comments on ISO 18626 to before 24th June 2016.


14 March 2016

ISO 18626 meeting at IFLA 2016 - During the IFLA World Library and Information Congress, (13 - 19 August 2016 in Columbus, Ohio, US) the ISO 18626 editor group is hosting a meeting about ISO 18626, its current status and implementation plans. This meeting will take place on August 17, 2016 at the OCLC Convention Centre (Room C124 & C125) from 9 am to 12 noon. Registration information will be provided at a later date.


13 April 2015

ISO 18626 Newsletter #1


15 July 2014

ISO (International Organization for Standardization) published ISO 18626 Information and documentation -- Interlibrary Loan.

The full press release is available




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