Making publicly funded research results freely available is both a right thing to do and a crucial condition to promote and advance science and scholarship. However, navigating the open science requirements under the Horizon Europe Model Grant Agreement (MGA) can be challenging for researchers. Therefore, to support EU-funded researchers, including ERC grantees, in meeting their open science obligations a new study has been published with the support of ERC.

This paper provides recommendations on selecting suitable repositories for depositing research outputs. This inventory is not a whitelist or an endorsement. It rather is intended as a resource for researchers, research institutions, and repository managers to assess which repositories are suitable for their needs and can facilitate compliance with the MGA requirements. The aim is to promote open science, fostering collaboration among researchers across Europe and beyond.

The study updates a previously published one and is based on a new methodology, presenting a new classification. The study classifies repositories into four categories: Exemplary, Essential, Close to Essential, and Data Inconclusive. Repositories classified as Exemplary or Essential meet all the mandatory open science requirements of the Horizon Europe MGA. Those classified as Exemplary also satisfy the recommended requirements. The Close to Essential readiness level identifies repositories that are only partially able to support the mandatory requirements of open science under the Horizon Europe MGA.

The study can also be used as a guide to complete a self-assessment, which will help determine whether a repository not analysed in the study meets the required criteria. It will also help repository managers to update or design their repositories to make them ready to facilitate compliance with the MGA requirements. Some popular repositories may not allow Horizon Europe beneficiaries, including ERC grantees, to comply with all their open science obligations. Researchers who wish to use these repositories can deposit a second copy of the publication in a repository that enables them to meet all the requirements.

While the current study intends to provide a foundation for further work in this area, the ERC is not planning further updates, but rather hopes that the scientific community will take over this task.