Commissioned and governed by Jisc’s strategic groups with input from Delta Think, an open access (OA) data and analytics company, this report explores the OA landscape and the particular role of transitional agreements (TAs), with the aim of gathering evidence, promoting discussion in the higher education and research sectors, and includes recommendations for action. The review responds to the following questions: What proportion of scholarly literature is OA? What impact have Jisc-negotiated TAs had on open access to UK research publications? What effect have TAs had on costs for UK higher education providers?How far have TAs facilitated author compliance with funder requirements? To what extent have TAs enabled greater transparency around publisher OA processes for the academic sector? This is a shortened version of the full report, which does not include appendices.