Guidance on Digital Object identifiers (DOI) and International Standard Book Numbers (ISBN)

Updated on 7 July 2023

Guidance for researchers on which unique identifiers to use and how to obtain one for a publication or dataset.

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Once a publication has been produced, it may be useful to add a unique identifier, to make it easier to locate and identify. There are two different identifiers to consider, depending upon the method of distribution you envisage:

ISBN (International Standard Book Number)

There is no legal requirement for a book or monograph to have an ISBN. It is primarily to allow for more efficient marketing, dissemination and identification of outputs by universities, authors, libraries, booksellers, wholesalers and distributors. It allows others to identify the specific ‘version’ of that publication, which potentially might be ambiguous via a citation reliant upon author/title/publication date only.

It helps with cataloguing and if you wish to sell or distribute a publication through major bookselling chains or internet booksellers, you will usually be required to have an ISBN. In the UK Nielsen Books handles all applications for new ISBNS.

You will need to register your publisher details with them, and then purchase either a single or bulk purchase of ISBNs. A single ISBN currently costs £89.00 [last revised August 2019], and a block of 10 ISBNs costs £164.00.

DOI (Digital Object Identifier)

A digital object identifier (DOI) is a string of characters which uniquely identifies an object. DOIs are often used for journal papers but can also be used for other publications and datasets.

  • DOIs for research data are administered by an international organisation called DataCite.
  • DOIs for publications are administered by an international organisation called CrossRef.
  • The British Library provides the UK node of DataCite.
  • DOIs are particularly useful because they can easily be turned into DOI links.  In other words, they both identify an object and take you to it (or to an internet page which tells you how to access the object).  Any changes in location are updated in the central registry of DOIs.

Giving your data or publication a DOI:

  • means that usage of your data/publication can be followed as others use and cite it.
  • makes the data/publication uniquely identifiable.
  • means you will always be identified as the creator of the cited data/publication.
  • means your data/publication can always be located with a simple web search.

Publishers normally assign DOIs to the items they publish, and are currently most employed in journal articles. The LLC can supply DOIs for in-house publications, produced within the University, either within PURE, or another University data store.

The Library and Learning Centre can now provide researchers with a Digital Object identifier, or DOI, for their publications or datasets. The LLC has a subscription to CrossRef which enables the generation of DOIs for publications, and also with DataCite, which provides the same service for datasets.

If you wish to apply for a DOI for a dataset, please contact


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