What is Subscribe-to-Open (S2O)?

‘Subscribe-to-Open’ is an approach to converting subscription journals to open access. It is an alternative subscription model which enables libraries to use their collections budgets to support open access publishing. Existing library customers are asked to continue to subscribe every year, and if all subscriptions are renewed, EDP Sciences publishes that year’s content in open access.

Which journals participate in EDP Sciences’ S2O programme?

Six journals participate in the mathematics Subscribe-to-Open programme led by EDP Sciences and the French Société de Mathématiques Industrielles et Appliquées (SMAI). The maths journals currently published in open access under the S2O programme are:

Astronomy & Astrophysics (A&A) will be published under a Subscribe-to-Open model in 2022. Provided the subscription renewal campaign is successful, A&A will publish its content in open access.

Why should I continue to subscribe under a S2O model?

  • Your institution is guaranteed access to content it values. If subscription revenues fall, e.g. because institutions decide to cancel their subscription payment, or delay their payments significantly, the content from that year will go behind a paywall and only the subscribers will still have access.
  • Your subscription payment will show your commitment to the long-term sustainability of open access.

Are there additional benefits for subscribers?

For the Mathematics S2O programme:
As an additional benefit, subscribers to the mathematics journals will be given reserved access to several years of archives, depending on the journal.

What are the benefits for authors?

  • Articles are published under a CC-BY 4.0 license allowing authors to retain the copyright.
  • The license enables authors to be fully compliant with the open access requirements of their institution or funding organisation(s) such as national research agencies and funders adhering to "Plan S".
  • Publishing your article open access means your research is available immediately to researchers globally meaning your work is more likely to be read and cited and have bigger impact.

Are there charges to publish in the participating journals?

The Subscribe-to-Open model aims to transition subscription journals to open access, using existing subscription workflows and channels, and without changing the financial structure of the journal. This is a cost-neutral operation.

  • The journals in the mathematics S2O programme are funded by subscriptions only. Under S2O, authors can publish in the participating mathematics journals in open access, free of charge.
  • Astronomy & Astrophysics has a more complex financial structure. While subscriptions fund the publishing costs of the journal, the editorial costs are funded by contributions from Board member countries, or page charges for authors of non- member countries. Under S2O, editorial costs will continue to be funded by Board member contributions and page charges, while subscriptions will be used to cover the open access publication of the journal. If the S2O program is successful, authors from sponsoring countries can therefore publish in open access free of charge, while authors from other countries remain liable for page charges to fund the editorial process of their article.

What will be open access and when?

Provided subscriptions are renewed, journals participating in the S2O programme will publish newly accepted content in open access.

There is no lock-in, the decision whether the year’s content will be published in open or gated access will be made annually. With the continued support from subscribers, the participating journals remain open access without periods of interruption.

The opening of each year’s content is contingent on sufficient participation from library customers.

Content published in open access remains in open access for ever.

How is S2O subscription revenue used by EDP Sciences?

EDP Sciences and the partner journals participating in the S2O program are committed to financial transparency. Every year, EDP Sciences and SMAI released a comprehensive Transparency Report to make a broad range of financial information publicly available. A similar initiative is planned for Astronomy & Astrophysics.

What is the difference between gated access, free access, and open access?

For journals/content in gated access, articles are only available to subscribers of the journal or to those who pay per view.

For journals/content in free access, articles are free to read for everyone, without a payment. For example, content can be made free to read for a limited period for editorial reasons or promotional purposes. These articles do not hold a CC-BY 4.0 license.

Open access is more than free access. Knowledge is open if anyone is free to access, use, modify, and share it. The author of an open access article holds the copyright on it instead of transferring the copyright to the publisher. A Creative Commons license is a way to give permission for others to share and adapt the content in advance. EDP Sciences uses the Creative Commons CC-BY 4.0 for its open access content.

Open access is in constant evolution. EDP Sciences actively explores new options to find the best open access solutions for our partners. Articles published in open access under the EDP Sciences S2O model are published in immediate and perpetual open access with a CC-BY 4.0 license.

I represent an institution whose members use and value the content of journal(s) published in EDP Sciences’ S2O programme. How can I join the programme?

EDP Sciences welcomes new subscribers joining the programme at any time. Your participation will help secure the open access publication of the journal. To Subscribe-to-Open, or if you have any questions, do not hesitate to contact us at: This email address is being protected from spambots. You need JavaScript enabled to view it..

As an individual or an institution, I would like to support the EDP Sciences’ S2O programme. How can I help?

If you or your laboratory or institution would like to support the EDP Sciences’ S2O programme and contribute to the long-term open access publication of the participating journals, please contact This email address is being protected from spambots. You need JavaScript enabled to view it.. It is possible to use ANR (in France) or Wellcome Trust funding to support a Subscribe-to-Open programme.

Is publishing in S2O journals compliant with Plan S?

The Subscribe-to-Open model is supported by Coalition S, see https://www.coalition-s.org/coalition-s-endorses-the-s2o-model-of-funding-oa/

If journals included in the S2O programme receive subscription renewals required year after year and are published in full open access, articles will be published in open access with a CC-BY license, and authors will be fully compliant with funder mandates such as Plan S.

If subscriptions are not renewed, and a journal is therefore not published in OA but remains in gated access, authors will not be able to publish their article in the journal in open access free of charge. Plan S funded authors can however be compliant with such mandates via the “green route”, and deposit their author accepted manuscripts, in a preprint repository with a CC-BY license and without embargo. See EDP Sciences self-archiving policy.

Further Information

Further general information and contact: This email address is being protected from spambots. You need JavaScript enabled to view it.

Information about the mathematics Subscribe-to-Open programme

Information about the Astronomy & Astrophysics Subscribe-to-Open programme