ISRCTN is a publicly accessible clinical trial registry that accepts all research studies; both prospective and retrospective registrations are accepted. It is officially recognised by the World Health Organisation (WHO) and the International Committee of Medical Journal Editors (ICMJE) as a primary clinical trials registry.

On 20th October 2021, the Health Research Authority (HRA) announced its partnership with ISRCTN, a World Health Organisation (WHO) recognised UK registry. This partnership will be fulfilling one of the commitments pledged in the HRA’s Make it Public Strategy; that of ensuring all clinical trials approved in the UK appear on a public registry recognised by the WHO.

All clinical trials of Investigational Medicinal Products (CTIMPs) and combined trials of an investigational medicinal product and an investigational medical device (IMP/device trials) submitted on or after 1 January 2022 for combined review in the new part of IRAS will be automatically registered on ISRCTN registry. There is no charge to sponsors or researchers for automatic registration, and this applies to both commercial and non-commercial sponsors.

The HRA has also prepared a Frequently Asked Questions (FAQ) page to provide more information about the automatic registration process.

Instructions for registering on ISRCTN (for non-CTIMPS):

  • Please create an account at and click on “Register you study”. For help completing the application form, please follow the blue tooltips, download ISRCTN guidelines (PDF), read the definitions page, and watch instructional videos.
  • Ethics approval details can be added before or after the study is registered.
  • ISRCTN is required under the WHO standards for trial registration to obtain written third-party confirmation that a trial exists. Acceptable evidence includes letters from ethics committees, funding agencies or government regulatory authorities. We will record that this information has been provided and store the document, but the evidence will not be publicly displayed. Please send written third-party confirmation as an attachment.
  • Researchers are encouraged to provide their study protocols, statistical analysis plans and participant information sheets and to add links to publications and datasets.

Frequently asked question

The service currently only applies to CTIMPs and IMP/device trials submitted for combined review via the new part of IRAS. However, the HRA has pledged that this service will be rolled out to other types of clinical trials in time.

Registration on ISRCTN will meet the condition of a favourable REC opinion so registration on is not required. If there are extraordinary circumstances that would require you to register your trial on as well, please note that you will need to report results on all sites. 

Imperial sponsored non-CTIMP studies will have the option to register on either ISRCTN or depending on study team preference and funding. Please note that registration on is free of charge, while registration of studies on ISRCTN will be subjected to a registration fee of GBP 226 + tax when applicable.

Once a trial has received full ethical approval, data from IRAS will be transferred into the ISRCTN system to generate a submission. The submission will be processed by ISRCTN, who will contact the investigator or sponsor representative to collect any missing information. A registration number will be issued by ISRCTN when a record is complete, which will also be shared with the HRA and NIHR CRN.

Studies registered on ISRCTN should have either a results publication or a basic results summary added within 12 months of the overall end date.

The HRA will automatically register your trial with ISRCTN when all the approvals have been successful. However, if you would like to register your trial earlier before approval for the trial is achieved, the HRA recommends that you contact ISRCTN directly to arrange this. You can find their contact details here.

However, this also implies that your study details won't be automatically sent to ISRCTN via IRAS.