The biggest open-access experiment inside scholarly societies right now is not another read-and-publish deal or a new article processing charge schedule. It is a subscription renewal form with a deadline attached. Subscribe-to-Open, usually shortened to S2O, inverts the familiar bargain: libraries keep paying roughly what they already pay, and if enough of them renew by a set date, that year's articles become free to read for everyone under a Creative Commons licence. If enough do not, the volume stays behind the paywall and the subscribing library keeps the access it paid for.
That conditionality explains both the model's appeal and its fragility. Society publishers like S2O because it keeps subscription revenue intact while removing author-facing fees; librarians like the idea but must decide whether to renew a title that may become free anyway; researchers, particularly those without grant funds, like the absence of article processing charges and still want the piece open on publication day.
How a renewal letter becomes an open-access switch
Article processing charges, or APCs, work on the author side: anyone who publishes pays a fee, and the resulting article is open. S2O works on the reader side: institutional subscribers pay the same subscription charge, and the society uses that income to open the current volume for readers everywhere. Authors pay nothing, no matter the outcome.
A society sets a participation threshold, usually expressed as a percentage of prior-year subscribers or subscription revenue. By a fixed date, often late in the year, the publisher counts institutional renewals. If the threshold is met, the coming volume carries a Creative Commons licence, commonly CC BY, immediately on publication. If the threshold is not met, the journal reverts to subscription access for that volume. Renewing libraries lose nothing; authors who submitted the manuscript lose nothing; the publisher and its society owner absorb the difference in public impact.
The society scoreboard, with names attached
Annual Reviews, the nonprofit that popularised the model, opened five journals in its 2020 S2O pilot, including Annual Review of Public Health and Annual Review of Virology. The organisation now reports that all 51 of its review journals run through S2O annually, a rare example of a subscription publisher converting an entire list one volume at a time. Its Subscribe to Open page publishes the renewal updates that library committees rely on.
The Company of Biologists followed with Development, Journal of Cell Science and Journal of Experimental Biology, three journals whose editorial communities had been paying APCs under hybrid arrangements. The American Society for Microbiology put its subscription titles into S2O for the 2021 volume year, an important test because ASM is a scientific society with a large professional membership rather than a platform publisher. IWA Publishing, the small publisher owned by the International Water Association, moved its water and environment journals to S2O. Berghahn Books' Open Anthro programme applied the same mechanism to a cluster of anthropology journals, showing that the model extends beyond biomedical and water sciences. The Subscribe to Open Community of Practice now tracks a growing group of publishers trying the same conditional flip.
Here's the catch
S2O relies on a collective action problem. A university library facing a flat budget can look at a journal that will be open if enough other customers renew and decide to keep the money. If enough libraries make the same rational choice, the threshold is missed, the journal stays closed, and only the renewing institutions retain access. The model turns every renewal season into a standoff between institutional self-interest and collective public access.
Most societies do not publish their thresholds. Some publish renewal rates after the fact; fewer publish the exact number needed before the deadline. That opacity asks library committees to take a publisher's word at a moment when price transparency is gaining regulatory push, particularly through Plan S. If the threshold is not disclosed, a library cannot evaluate whether its own renewal is the marginal one that opens the journal. It is being asked to renew on trust in a market where trust has not been the leading currency.
There is also a mismatch between S2O's conditional nature and funder compliance. Plan S and several research agencies require immediate open access with a licence that is not subject to an annual renewal lottery. A journal that might open this volume but might not open next volume creates a compliance gap for grant reporting systems, even if the model usually holds. Backfiles add a second limit: S2O generally applies to current volumes, so a reader who opens a new article may still hit a paywall when following a citation to a paper published before the first S2O volume.
Hype versus reality, graded
- Author-side fee removal: reality, high. S2O journals do not bill authors, so early-career researchers in low- and middle-income countries are not entering a waiver queue to publish. That is a clear contrast with APC-based gold open access.
- Cost reduction: hype, mostly. S2O does not lower what institutions pay. It moves the licence from subscribed access to open access only if enough institutions continue paying the same amount. The subscription line item survives; the invoice does not disappear.
- Opening the scholarly record: reality, conditional. When renewal thresholds hold, entire volumes become openly available in a way that hybrid journals rarely achieve. The condition is the problem: open access arrives as an annual verdict, not as a standing property of the article.
- Structural reform: hype. The same negotiating parties, the same bundled invoices, and the same information asymmetry often remain. S2O can ease author-side inequity without fixing the reader-side market concentration that made subscription costs so hard to shift.
What a society board should ask before signing
The strongest S2O programmes disclose their renewal threshold before the subscription deadline. Annual Reviews has moved further than most by publishing an annual update on participation; other societies could copy that without weakening their negotiating position. Public thresholds turn a private decision into a shared commitment.
Consortial pledges help too. When a national consortium agrees to maintain subscriptions for three years, a society no longer lives or dies on a single November spreadsheet. That multi-year discipline is the difference between a genuine transition and a perpetual experiment.
Licence terms matter for funder compliance. A society should opt for CC BY or another licence that major research funders recognise, because a conditional model already draws scrutiny from Plan S. The cOAlition S framework accepts S2O under specific conditions; societies should verify those conditions before claiming compliance to their author communities.
There is a related financial question for institutions comparing S2O titles with so-called diamond journals and traditional subscription packages. The earlier AcademicJobs look at the Plan S price transparency journal comparison service explains why item-level cost data is replacing package-level opacity. The European diamond open access funding pressure, covered separately by AcademicJobs, shows what happens when neither subscriptions nor APCs support a journal. S2O looks better from a researcher's chair when the invoice is visible.
The last word
The last word belongs to the people who never see the invoice. A researcher cares whether the article is readable immediately by a colleague in Nairobi who works from a small university library, a clinician in São Paulo, and a doctoral student in Vienna. S2O makes that possibility conditional on a renewal decision made months earlier in a library office.
Conditional access is not access. Society journals have gained credibility by removing author fees and opening volumes year after year, but the model still asks researchers to wait for an administrative threshold to clear before the DOI resolves the same way everywhere. For the researcher at the bench, that annual moment of suspense is the whole story.
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