Horizon Europe Will Not Reimburse a Hybrid Journal APC

Because the rule is about the journal rather than the article. Horizon Europe treats an article processing charge as an eligible cost in a fully open-access journal and not in a hybrid one, whatever the resulting article looks like. The article you published complies with the open-access obligation; the invoice simply is not a cost the grant will carry.

A journal that sells subscriptions and also offers, for a fee, to make individual articles open. The test is what the journal is, not what your article became. A journal in which every article is open, funded by charges rather than subscriptions, is fully open access; a journal in which most articles sit behind a paywall and yours does not is hybrid.

Yes, and it is the route most often missed. Deposit the accepted manuscript in a trusted repository at publication, licensed CC BY, with no embargo. That satisfies the obligation on its own. The article processing charge buys a better-looking version of record and nothing more as far as the grant agreement is concerned.

CC BY permits reuse with attribution, which is what the policy is aiming at. For articles it is the requirement. For monographs, book chapters and other long-form outputs, CC BY-NC or CC BY-ND are permitted, which is a genuine difference and one that matters if you are publishing a book rather than a paper.

Your institution’s repository, or a recognised disciplinary one such as arXiv, Europe PMC or a subject archive with a stable preservation commitment. A personal website, a lab page or a commercial research-sharing network is not one, which catches people who have uploaded the paper somewhere and reasonably believe they have finished.

A sentence in your submitted manuscript asserting that a CC BY licence applies to the accepted version. It matters because some journals will only accept it if it is present at submission — adding it after acceptance is too late. Where your route to compliance is repository deposit rather than an article processing charge, this is the sentence that makes it work.

Both, and the strictest of each. NIH requires the accepted manuscript in PubMed Central on acceptance; Horizon Europe requires immediate deposit under CC BY and limits which charges it will pay. Satisfying both means an immediately deposited accepted manuscript under CC BY in a journal whose charges are either reimbursable or not incurred — which is a real constraint on the journal list and belongs at the start of the project.