GP registration data include people registering with a GP for the first time where their previous address was outside of the UK. If someone moves within the UK and registers with a new GP practice, however, this and any subsequent registrations will not be flagged as a migrant registration. GP registration is not compulsory and some migrants will only register with a GP when they require medical attention. As such, these data should not be considered to be an accurate measure of all immigration inflows.
To learn more about the use of GP registration data in the production of official migration statistics, please visit the ONS website.