This Practice Note explains the offences which can be committed by jurors both during and after a trial or an inquest. This note covers the information which must be provided to jurors under the Criminal Procedure Rules 2020, SI 2020/759 (CrimPR) and the offences relating to a failure to attend when required under the Juries Act 1974. It also explains the offences introduced by the Criminal Justice and Courts Act 2015 including research by jurors, sharing such research with other jurors, engaging in other prohibited conduct and disclosing jury deliberations.