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The evaluation of digital preservation infrastructure and workflows through self-assessment, audit and certification is of central importance to the ADS. Such assessments ensure that the ADS can be confident that the procedures, processes and workflows adhered to are ‘fit for purpose’ and cultivate confidence from amongst our designated community that we are a ‘trusted repository’.

To ensure the highest level of compliance and service provision, and build trust with its designated community, the ADS has submitted itself to formal review undertaken by external service providers and agencies. Consequently, the ADS has been awarded the Data Seal of Approval and its replacement the CoreTrustSeal, is a regular member of the World Data System (WDS), holding the WDS Certification of Trustworthy Digital Repository, and has been awarded National Archive Accreditation, via their assessor body in England, The National Archives.

To aid transparency all policies and procedures are made accessible through our website.

Core Trust Seal Logo


The ADS holds CoreTrustSeal certification (2023-2025).

The full transcript of the ADS’ application is available from the CTS website.

CoreTrustSeal Data Repository certification replaces the both DSA certification and WDS Regular Members certification and is the culmination of a cooperative effort between DSA and WDS under the umbrella of the Research Data Alliance. The CoreTrustSeal assessment is based on the DSA–WDS Core Trustworthy Data Repositories Requirements catalogue and procedures. As such the requirements ensure holders adhere to the core characteristics of trustworthy data repositories.

Find out more about the CoreTrustSeal.

National Archives AccreditationThe logo defining an Accredited Archive Service

The ADS holds National Archive Accreditation, as assessed by their body in England, The National Archives (2023-2029). The ADS is the first ever digital-only archive service to receive this accreditation.

National Archive Accreditation is the UK quality standard that recognises good performance in all areas of archive service delivery. Accredited Archive Services ensure the long-term collection, preservation and accessibility of our archive heritage. Achieving accredited status demonstrates that an archive has met clearly defined national standards relating to management and resourcing; the care of its unique collections and what the service offers to its entire range of users.

Find out more about National Archive Accreditation.

World Data Systems logo

ISC – World Data System (WDS)

The ADS is a ‘regular member‘ of the WDS and holds the WDS Certification of Trustworthy Digital Repository. The ADS also adheres to the WDS Data Sharing Principles.

As part their accreditation WDS Regular Members must fulfil the WDS membership requirements and undergo a transparent and objective certification procedure to ensure their trustworthiness in terms of authenticity, integrity, confidentiality, and availability of data and services. Such certification is vitally important because it promotes trust and confidence in the usability and persistence of shared data resources.

Find out more about the World Data System (WDS).

Data Seal of Approval (DSA)Data Seal of Approval Logo

The DSA was awarded to digital repositories that met a robust set of sixteen requirements. The ADS received the Data Seal of Approval in March 2011. This was renewed in 2013 when new Data Seal of Approval standards were released for 2014-17 and extended in 2017-2019. The DSA was replaced by the CoreTrustSeal in 2018.

A post ‘ADS and the Data Seal of Approval – case study for the DCC‘ describes how and why we made the DSA application, with an updated post Data Seal of Approval: we’ve still got it!‘ in 2013.

Digital Preservation Coalition

The ADS is also an associate member of the Digital Preservation Coalition (DPC) and was awarded the DPC’s Decennial Award in 2012 for the most outstanding contribution to digital preservation over the last decade.


On-going self-assessment by repository staff ensures the currency of procedures and practices, builds robustness into workflows and safeguards current preservation and dissemination processes. These activities are also subject to a process of more formal and regular assessment, with an annual review of all preservation activities an integral feature of the repositories calendar. These are carried out in line with current self-assessment standards including:

Logo for the Digital Preservation Coalition (DPC) Rapid Assessment Model (RAM)