National data repository requirements now differ sharply by jurisdiction: the UK coordinates through UKRI’s Concordat on Open Research Data and a planned National Data Library, the US relies on agency-specific mandates such as the NIH Data Management and Sharing Policy layered on the OPEN Government Data Act, and the EU binds Horizon Europe funding to mandatory FAIR data management plans routed through the European Open Science Cloud. All three converge on the FAIR principles as the technical baseline, but they diverge sharply on enforcement, centralisation and what “as open as possible” means in practice.
A national data repository is a government- or funder-endorsed infrastructure (or federated network of infrastructures) for depositing, curating and providing persistent access to datasets produced by publicly funded research, so that they meet the FAIR standard of being Findable, Accessible, Interoperable and Reusable. No single global rulebook defines what such a repository must look like — which is precisely why the UK, US and EU have built three structurally different systems around the same FAIR foundation.
- What counts as a national data repository?
- How does the UK mandate research data repositories?
- How does the US enforce data-sharing requirements?
- How does the EU mandate FAIR data through Horizon Europe?
- Where do the three approaches converge and diverge?
- Common questions on national data repository mandates
- What this means for institutions and researchers
What counts as a national data repository?
A national data repository is infrastructure, endorsed at government or funder level, that stores research datasets with persistent identifiers, standardised metadata and defined reuse licences. The FAIR data principles — first formalised in Scientific Data in 2016 — define the technical bar: data and metadata must be findable via persistent identifiers, accessible over open protocols, interoperable through shared vocabularies, and reusable under clear provenance and licensing.
Crucially, FAIR does not mean unconditionally open. The dominant policy language across all three jurisdictions is some variant of “as open as possible, as closed as necessary” — datasets with legitimate privacy, security or intellectual-property constraints can remain FAIR while access to the raw data itself stays restricted, provided the metadata is still discoverable.
How does the UK mandate research data repositories?
The UK’s approach is coordinated centrally through UK Research and Innovation (UKRI) rather than fragmented across individual funders. The Concordat on Open Research Data, agreed by UK funders and sector bodies, sets the expectation that publicly funded research data should be made openly available with as few restrictions as possible, in a timely and responsible manner.
UKRI has been developing a harmonised open research data policy to replace the varying requirements previously set by its individual research councils, with a more explicit alignment to FAIR principles than the original Concordat text. The UK does not run one single mandatory repository for all disciplines; instead it combines a cross-disciplinary resource — the UK Data Service, holding the country’s largest collection of economic, population and social research data — with discipline-specific data centres. A National Data Library initiative is also under development. Enforcement runs through grant conditions rather than statute.
How does the US enforce data-sharing requirements?
The US combines a government-wide legal baseline with agency-specific enforcement, producing a federated rather than centralised system. The OPEN Government Data Act codifies the principle that federal government data — including federally funded research outputs captured by agencies — should be open and machine-readable by default, operationalised through the Data.gov catalogue.
The sharpest enforcement sits with individual funding agencies. Under the NIH Data Management and Sharing (DMS) Policy, effective since January 2023, NIH-funded researchers must submit a DMS Plan describing how scientific data will be managed and shared, with FAIR principles strongly encouraged. The National Science Foundation requires a Data Management Plan for all proposals and supports deposit through disciplinary repositories and its own NSF Public Access Repository (NSF-PAR). This gives communities flexibility to choose fitting repositories, at the cost of one unified national research-data repository.
How does the EU mandate FAIR data through Horizon Europe?
The EU operates the most centrally binding framework of the three. The Directive on open data and the re-use of public sector information requires member states to establish national policies for open access to publicly funded research data on an “open by default” basis, explicitly aligned with FAIR principles. For research funded under Horizon Europe, making data FAIR is a mandatory grant condition, not a recommendation: funded projects must produce a Data Management Plan and comply with FAIR requirements as a condition of the award, under the same “as open as possible, as closed as necessary” test used elsewhere.
Infrastructure is built around the European Open Science Cloud (EOSC), described by the European Commission as a federated environment intended to become a “web of FAIR data and services” spanning all scientific disciplines. Within that federation, researchers commonly deposit through the general-purpose repository Zenodo — built and operated with CERN — while the Community Research and Development Information Service (CORDIS) serves as the EU’s public repository of record for funded project information.
Where do the three approaches converge and diverge?
All three jurisdictions treat FAIR as the technical baseline and all three qualify openness with a “necessary restriction” clause. The differences lie in enforcement mechanism, degree of centralisation, and whether a single flagship repository exists.
| Feature | UK | US | EU |
|---|---|---|---|
| Primary instrument | UKRI Concordat on Open Research Data (evolving to a harmonised FAIR-explicit policy) | OPEN Government Data Act; NIH DMS Policy; NSF Public Access Policy | EU Open Data Directive; Horizon Europe grant conditions |
| Legal basis | Funder policy condition | Federal statute plus agency policy | Legally binding directive plus grant condition |
| FAIR status | Increasingly explicit in new UKRI policy | Encouraged, embedded in agency plans | Mandatory for Horizon Europe-funded projects |
| Data management plan required | Yes, for UKRI funding | Yes, for NIH and NSF funding | Yes, mandatory for Horizon Europe |
| Repository model | Centralised flagship (UK Data Service) plus disciplinary centres | Federated (Data.gov, NSF-PAR, disciplinary repositories) | Federated supranational (EOSC, Zenodo, CORDIS) |
Common questions on national data repository mandates
What are the FAIR data principles required by UKRI?
UKRI requires funded researchers to make outputs Findable, Accessible, Interoperable and Reusable, aligned with its Concordat on Open Research Data. UKRI councils frame this as maximising the impact, visibility and citation of research while applying the “as open as possible, as restricted as necessary” test to data with legitimate sensitivities.
Does the NIH require a data management and sharing plan?
Yes. Since 25 January 2023, the NIH Data Management and Sharing (DMS) Policy requires funded researchers to submit a DMS Plan describing how scientific data will be preserved and shared. NIH strongly encourages applying FAIR principles when selecting repositories and structuring metadata for that plan.
Is FAIR data mandatory under Horizon Europe?
Yes, unlike the UK’s evolving policy and the US’s encouraged-but-agency-specific approach, Horizon Europe makes FAIR data management a binding grant condition. Funded projects must submit a Data Management Plan and comply with FAIR requirements, subject to the same necessary-restriction exceptions used across all three jurisdictions.
Is there one single national data repository researchers must use?
No jurisdiction mandates a single universal repository. The UK combines a flagship service (UK Data Service) with disciplinary centres; the US runs a federated system across Data.gov and agency repositories such as NSF-PAR; the EU federates access through EOSC, Zenodo and CORDIS. Researchers typically choose the repository matching their discipline and funder requirements.
What this means for institutions and researchers
For research administrators managing multi-jurisdictional funding, a single data management plan template cannot satisfy all three regimes. Compliance teams must map deposit requirements per funder rather than assume FAIR-labelled data automatically meets every mandate’s specific repository, licensing and metadata conditions.
The trend line points toward convergence. The UK’s move to a harmonised, more explicitly FAIR-aligned UKRI policy and the EU’s EOSC federation both signal a shift from fragmented rules toward unified infrastructure. The US remains the outlier: its federal open-data statute operates largely independently of agency-specific mandates from NIH and NSF.
Institutions should treat “FAIR” and “open” as related but distinct compliance targets. A dataset can be fully FAIR — persistently identified, well-described, licensed — while remaining access-restricted for legitimate reasons in every jurisdiction covered here. Repository choice and data management plan content should be checked against the specific funder mandate, not a generic FAIR checklist.