Random mandatory drug testing (traditional drugs)

The percentage of random mandatory drug tests which show drugs to be present, hence a downward trend is positive. This measure excludes tests for new psychoactive substances.

The values for 2018/19 onwards are calculated using a new weighted methodology - please refer to the relevant publication for more details.

The data source is for the summary is HM prison and probation service annual digest, and the data source is for the details below is prison performance ratings (annual).



  • Data is not always available for, or applicable to, every prison; and the list of prisons will vary year on year due to closures and newly opened establishments;
  • Prison functions (Male Local etc.) refer to the function of the prison in the most recent year shown. The function of a prison may have been different in previous years;
  • A small number of prisons which are listed separately in the above table are physically co-located and cannot be distinguished on the map;
  • Contains OS data © Crown copyright and database right 2023;
  • Contains Royal Mail data © Royal Mail copyright and database right 2023;
  • The markers on the map are indicative only. For further information on a prison, or for details of a prison's location, please consult the Ministry of Justice prison finder.