International Clinical Trials Registry Platform (ICTRP)

The Universal Trial Number (UTN)

The aim of the Universal Trial Number (UTN) is to facilitate the unambiguous identification of clinical trials. The UTN is not a registration number.

The UTN is a number that should be obtained early in the history of the trial. The UTN should:

  • become permanently attached to the trial
  • be used whenever information about the trial is communicated
  • become part of the trial's identity
  • be documented in the trial protocol
  • be submitted every time the trial is registered

It is recognized that some UTNs will be attached to trials that do not progress; that is, trials that never become fully developed protocols and that never recruit participants. Some UTNs will therefore never appear attached to a registered trial.

UTN - Frequently Asked Questions

:: When should a UTN be obtained?
:: How can we obtain a UTN?
:: Who should obtain the UTN?
:: How many UTNs should a trial have?
:: What should we do with the UTN?
:: Is the UTN mandatory?
:: What should we do if a trial registry does not have a separate field for the UTN?
:: How will the UTN work?
:: What if my trial was registered before the UTN?


The ICTRP would like to thank the South Asian Cochrane Centre at the Christian Medical College, Vellore, India for the contribution resulting in the creation of the UTN allocation software.