Leiden University encourages making books available via open access, but does not mandate this for authors or editors. Please note: individual chapters within edited volumes do fall under the Leiden University Open Access policy and must be made available via open access no later than six months after the original publication date.

Most research funders impose open access requirements on books resulting from projects they have funded. NWO stipulates that all books (monographs and edited volumes) must be made open access—either through the publisher or a repository—with a maximum embargo period of 12 months. The European Commission and various other research funders are stricter, requiring immediate open access for books with no permitted embargo period. Therefore, always familiarize yourself with the open access conditions applicable to your research funding.

Just as with journal articles, there are several routes to making a book open access. Before signing a publishing agreement, consider which route you wish to use and ask the (prospective) publisher for an overview of the options and costs.

• Open access via the publisher – for a fee:
  Most publishers offer the option to make books open access—either in their entirety or chapter by chapter—upon payment of a Book Processing Charge (BPC) or individual Chapter Processing Charges (CPCs). Costs can vary significantly: from €5,000 to €18,000 for a book, or from €500 to €2,000 per chapter. You can find reliable open access book publishers via the Directory of Open Access Books. Specific models and terms are not centrally searchable; you will need to consult the publisher's website for details.
   
• Open access via the publisher – at no cost to the author/editor:
  Some publishers publish books open access without charging the author or editor a fee. However, these publishers often impose conditions: for instance, their programs may be open only to authors or editors from a specific institution, or to titles that fit within a particular series. The following resource provides an overview of these no-fee open access book publishers: Hopkins, K. (2026). ‘Where can I publish a book open access without (necessarily) paying a fee? A list of Diamond open access options’, via Zenodo: https://doi.org/10.5281/zenodo.20287653
   
• Open access via the repository:
  Even if a book is not published as open access, it can still be made openly available via the Leiden repository, Scholarly Publications. Agreements regarding this matter between authors/editors and their publisher must be included in the publishing contract; these are important negotiations to conduct well in advance. Typically, the following three aspects are open for discussion:
  • Scope: usually, 10–20% of the work can be made openly available (measured by page count).
  • Version: many publishers prohibit sharing the final version (Version of Record), but often allow a manuscript version or part of it—specifically the Accepted Manuscript (post-peer review)—to be made available via open access. Note: unlike with journal articles, book publishers rarely agree to the posting of a preprint (the submitted version)!
  • Embargo: sometimes publishers do not permit a book to be made open access immediately but do allow it after an embargo period of 12 to 36 months.

Note: under the Taverne Amendment, a book chapter can always be made open access via the repository after six months at no cost to the author; it therefore falls under the open access requirement of the Leiden University Open Access Policy.

• Leiden University does not have central funds to cover publication costs for open access books.
• Authors and editors can check with their faculty or institute to see if a budget is available.
• Research funders—such as NWO, ZonMw, the European Research Council (ERC), and the European Commission—generally allow their research funding to be used for the publication costs of open access books resulting from projects they have funded. Please note: funding may only be used if the entire book is made open access—meaning it cannot be used to make a single chapter open access within a collection that also contains chapters behind a paywall—and there is often a maximum amount of reimbursable costs.
• In addition to the project funding already awarded, authors and editors of NWO-funded projects can submit a supplementary application to cover the costs of publishing resulting books in open access. Further information on this funding mechanism can be found on the NWO webpage dedicated to the ‘Open Access Books’ call.
• Editors of edited collections can ask the publisher to split the open access costs by chapter, allowing chapter authors to (partially) secure the necessary funding. By combining funding per chapter in this way, splitting the costs makes it possible to publish some collections in their entirety as open access.

For many authors and editors, the open access model and its funding are key considerations when selecting a publisher for their book. Pay attention to the following aspects as well when choosing a publisher and considering a publication agreement:

• Copyright and licenses: since the copyright for a book written while employed by Leiden University belongs to the author or editor, the publisher requires permission to publish the work. It is best to grant this permission via a non-exclusive license; an exclusive license or a transfer of copyright is less desirable. See also the page ‘Copyright for authors’.
• Additional usage rights: the publishing contract can stipulate that you, as the author, retain rights to (part of) your work for your own use. This is useful if, for example, you wish to keep images, figures, or underlying data openly available to yourself or others, or if you want to use the book in your teaching. You can also agree on provisions regarding potential new editions of the book.
• Versions and formats: will the publisher produce only a digital PDF version, or also alternatives such as ePub or HTML? Will print copies of the work be produced as well?
• Editorial services: which tasks does the publisher handle, and which are the author's responsibility? For instance, who compiles the index and the apparatus of notes? How are the rounds of editing and corrections organized?
• Technical specifications: will the book (and potentially individual chapters) receive a ‘persistent identifier’, such as a DOI? Will the book be assigned an ISBN? How does the publisher ensure the books are visible in catalogs and databases? Does the publisher also provide reliable long-term archiving?

At many (small) book publishers, processes are not as streamlined or automated as authors and editors might assume. Therefore, always ensure you fully understand a publication contract before signing it—this applies to all publications, but especially to books. In particular, ask the open access team and/or the copyright information point to review the contract; you can contact them at openaccess@library.leidenuniv.nl.