The UK also has no border controls on exit. The Home Office keeps no record of who has left, AFAIK. Someone checks your passport to make sure you’re entitled to land somwhere else and that’s about it. For example, ferries to Europe - ferry employees are the only people who check your passport. I’m, pretty sure they are not logging any data for the govt - mostly it is a glance at, not a scan of, the passport, to ensure they won’t be landed with you if the other country decides you are not allowed in because no valid passport is held. This contributes to our immigration ‘problem’ because with no exit controls/records, the govt has no really accurate data on who is actually in the country.
