CORESkip to main content CORE COnnecting REpositories ServicesServices overviewExplore all CORE services Access to raw data API Dataset FastSync Content discovery Recommender Discovery OAI identifiers OAI Resolver Managing content Dashboard FAIR Certification Bespoke contracts Consultancy services Support usSupport us MembershipSponsorshipResearch partnership AboutAbout About us Our mission Team Blog FAQs Contact us Community governance Governance Advisory Board Board of supporters Research network Innovations Our research Labs CORE support for UK HEIs for REF 2029 As UK institutions’ focus begins to turn to REF2029, we continue our efforts to provide CORE members and UK HEIs with the most up to date information possible. The purpose of this document is to provide advice and recommendations to UK HEIs with regards to exposing data to CORE through their repositories to ensure optimum discoverability for Open Access scholarly articles. In this document, we use the term repository to refer to a system that the HEI will use for the purposes as defined in the Open Access Policy for REF2029 Significant changes in REF2029 Open Access Policy REF2029 Audit – Guidance Recommendations for exposing research outputs' metadata to CORE for REF2029 How CORE aggregation supports HEIs How CORE collects this information How can CORE help you Research Excellence Framework 2029 Go to the guidance Is your institution correctly set up for REF2029? Contact us 1. Significant changes in REF2029 Open Access Policy from 1st January 2026 It is important to note that for all in-scope outputs submitted to REF 2029 published between 1 January 2021 and 31 December 2025, the open access policy requirements for REF 2021 still apply. The revised policy requirements for REF2029 came into force for all journal articles and conference contributions on 1st January 2026. "Journal articles and conference contributions (with an International Standard Serial Number (ISSN) published between 1st January 2026 and 31st December 2028 are in-scope outputs for REF2029 and will be subject to the revised open access policy requirements for submission for REF in effect from 1st January 2026." The REF2029 Guidance makes a clear distinction between 'Published Open Access' (aka Gold, Diamond, Platinum) and 'Outputs shared by Deposit' (Green OA) For Published Open Access, where an output is made fully open access on publication (commonly termed 'Gold' open access, also 'Diamond' or 'Platinum'), conditional to it also fully meeting discovery, access and licensing criteria there is no further action required. There is however some nuance in the REF guidance regarding 'outputs shared by deposit' From 3.3.2: "Deposit: outputs subject to a post-publication embargo which are shared through institutional repositories ("Green" open access) are required to be deposited on publication rather than on acceptance for publication, which was the case in REF 2021." However, 7.2.3 then says: "Outputs shared by deposit: Where an output will be compliant via deposit in a suitable repository or other appropriate platform, a copy of such output should be deposited within three months of publication. This includes outputs subject to an allowable embargo requirement" This therefore indicates that ALL Green OA outputs must be deposited within 3 months of publication, not acceptance as was the case for REF2021. Changes in allowed embargo periods There has been a significant reduction in the allowed embargo periods for REF2029: Another notable change repository managers should be aware of concerns the grace period' previously allowed for REF2021; "Where the output has no or a 'zero' embargo period it must meet the access requirements as soon as possible and no later than one month after deposit." In the current REF2029 guidance, section 7 removes the explicit one-month grace period. From 1 January 2026, once deposited, outputs must be made fully accessible at the point of deposit, unless an embargo applies, in which case it must be made available after the embargo period has elapsed. Changes in Licensing requirements Currently, the funding bodies do not mandate any specific licence format or standard and recognise that researchers and institutions may choose from a variety of formats suitable for their output subject to meeting minimum standards identified. The current REF2029 guidance states: "Outputs should be shared as openly as possible; the funding bodies' strong preference is for licensing as CC-BY or other licence formats meeting this standard of openness. However, licensing outputs at CC-BY-NC or CC-BY-ND (including CC-BY-NC-ND) or licences meeting an equivalent standard of openness are also permitted." For the period 1 January 2026 to 31 December 2028 outputs shared by deposit (AAM), where subject to terms of a publication agreement limiting sharing and/or use of downloaded materials (embargo period) will not need to fully meet these licensing standards. They will however need to meet all other conditions for deposit, discovery and access. However, from 1 January 2029 all future in-scope outputs will need to fully meet open licensing standards, subject to any permissible exceptions. Having the correct licences clearly described in the metadata for your outputs is already an important step in making sure your content is as widely distributed and used as possible, from 2029 this will be an additional requirement to ensure compliance with REF policy. 2. REF2029 Audit – Guidance The final guidance for how the Open Access audit will be undertaken has not yet been publicly released. The current official statement is as follows: "The full audit guidance for REF 2029 is being developed. For open access, audit processes will broadly mirror the risk-based approach for REF 2021, subject to further review and potential adjustments." The previous guidance is accessible via the REF website, however the relevant sections from it are given below: 46. We will assess each HEIs' overall compliance with the REF 2021 open access policy by …. : iv. Using CORE, comparing the datePublished and depositedDate and identifying where the number of days between the two dates is greater than 92. And:49. Where there is insufficient evidence to demonstrate a robust and well-managed process for open access, we will identify a set of outputs from each submission made by the HEI, and request further information to verify whether they are compliant with the policy, or whether an exception applies. Outputs may be selected randomly, or based on information in unpaywall.org or CORE, or a combination of the two. We will select outputs that have been returned as compliant with the policy, and/or outputs that have been returned with exceptions. Consequently, at this time we are advising UK HEIs and CORE Members to follow the previous guidelines and the recommendations given below. We are currently engaging in dialogue with the REF Team (Research England), so we can continually keep you up to date with any and all changes to the published guidelines and how they may affect your institution.  3. Recommendations for exposing research outputs' metadata to CORE for REF2029 The following points are recommendations we make to institutional repositories to ensure their data is well represented in CORE. While these recommendations are not mandated by Research England, implementing them will both improve the quality of the data held by CORE to support REF2029 as well as increase the discoverability and visibility of the institutions' research outputs. We encourage institutions to expose their metadata using the Rioxx v3 metadata schema which provides native support for exposing deposit dates. CORE provides a metadata validator for Rioxx v3 in the CORE Dashboard and can provide methodological advice to Supporting and Sustaining members for implementing Rioxx v3. 1. Make sure that your institutional repository/ies are registered in CORE: We are constantly working towards CORE indexing all repositories available. However, as repositories sometimes change their web locations, platforms or some institutions introduce multiple repositories, we advise institutions to check that their repositories are registered and listed on the CORE's data providers page. 2. Adopt Rioxx as a data format: One of the key reasons for the development of the Rioxx metadata profile was to help institutions achieve compliance with the original REF 2021 Open Access Policy. While CORE can capture the data from repositories not supporting Rioxx, supporting Rioxx greatly reduces the complexity of the algorithm through which CORE acquires the data. The below recommendations detail which information should be shared in the metadata and how this information should be exposed in Rioxx. We further provide an example Rioxx metadata record with all information needed for REF 2029 correctly set. 3. Release deposit dates publicly, so that they are indexable by CORE: Following the release of Rioxx V3, The deposit_date is an attribute within the <dc:relation> property. If included, this attribute's value must be encoded according to the W3CDTF (a profile of ISO 8601) which typically follows the following format: YYYY-MM-DD. 4. We encourage repositories to expose the deposit date for each research output: Even when Rioxx is not implemented, and ideally to mark it as "Date Deposited:". For example, EPrints repositories typically display the deposit date on the page of a given record (an example at Open Research Online). This date must be the date of the first compliant deposit. We rely on the following definition of first compliant deposit. 5. Ensure that all records to be submitted to REF have a full text linked directly from the metadata: There are various ways of describing the link in the metadata and you can follow the guidelines for each one. In particular, we recommend storing the full text link in the dc:relation field with all the dedicated attributes if you are using the Rioxx v3 profile. In many other profiles the most appropriate place is the dc:identifier field. CORE supports most of the common profiles, so as soon as the data is stored according to the standards, it will be automatically checked. 6. Ensure that your repository OAI-PMH endpoint is operational: The OAI-PMH endpoint in your repository enables aggregators to collect data from your repository. The Confederation of Open Access Repositories (COAR) states that the real benefits of repositories come from interoperability which gives us the ability to exchange data within a network. This is currently realised by the OAI-PMH protocol. In the majority of cases, the OAI-PMH endpoint will be correctly working in your repository by default. To check its operation there are freely available validators that ensure the correct response of the endpoint. However, the validator does not fully ensure that the data from the repository could be indexed without issues, which could be a potential problem, especially for larger repositories. Any repository can register freely for the CORE Repository Dashboard account which enables the repository to check its indexing status. 7. Ensure outputs have a registered permanent identifier (PID): To ensure the REF research outputs can be unambiguously matched to the metadata in the repository, we recommend that institutions ensure that outputs have a permanent identifier (PID). An OAI identifier can be linked directly to each research output by the repository. CORE provides a global OAI Resolver built on top of the CORE research outputs aggregation system. Other permanent identifiers such as DOIs or PubMed IDs can also be made accessible via the record's metadata whether using Dublin Core or Rioxx V3. Below is a minimal example of a Rioxx record with the recommended fields populated: <!-- Example minimal Rioxx V3 record excerpt --> <rioxx xmlns="http://www.rioxx.net/schema/v3.0" xmlns:dc="http://purl.org/dc/elements/1.1/"> <!-- Core iden…