Question to the Home Office:
To ask Her Majesty's Government how many non-visa nationals whose permission to be in the UK expired, and for whom there was no record of departure, there were in each of the past five years.
The Home Office publishes statistics relating to departures by visa holders as part of its annual Exit Checks report (https://www.gov.uk/government/statistics/fifth-report-on-statistics-relating-to-exit-checks). The report includes the percentage of non-EEA visa holders whose leave expired with no initially identified departure in time, including both people for whom there was no record of departure and people with a confirmed late departure.
It is important to note individuals with no departure recorded were not necessarily non-compliant. There are known coverage gaps with the ISA system (most notably the Common Travel Area) which means individuals may have departed and not been recorded. In addition, information regarding a departure may have been received but not successfully matched against their arrival or visa by the system.