Wellcome has required it for a while.<p>Any papers you plan to use in the Research Excellence Framework for 2020 (for those not acquainted, an exercise every few years where UK universities get to say &quot;look how good we are, we published this many papers, please keep funding us&quot;) must be available as open access. It isn&#x27;t necessary for these papers to have gone the gold open access route (where you pay a *!&amp;^%-ton to the publisher), so you could instead upload the non-published version to a preprint server (which is a lot cheaper).