You are required to upload a copy of the Author’s Accepted Manuscript (AAM) to a repository, such as Pure. Acceptable embargo lengths are 6 months of scientific papers, and 12 months for social science and humanities papers. This must be done as soon as possible and at the latest upon publication.
Horizon 2020 has provided an addendum which can be added to publishing agreements which ensures authors have the rights they need to comply.
Paying to make your paper openly available is also acceptable and the cost can be reimbursed by Horizon 2020 if it arises during the duration of the grant. For guidance please get in touch with the Open Access Team. The article must still be uploaded to an appropriate repository.
Beneficiaries must aim to deposit at the same time as the publication the research data needed to validate the results presented in the deposited scientific publications ('underlying data') ideally in a data repository.