Beginning January 8, 2025, the United Kingdom will require that all non-European visitors complete an ETA prior to arrival in order to enter the country. All eligible non-Europeans can now apply (as of November 27th, 2024) for the ETA.
This requirement will extend to European passport holders starting April 2nd, 2025, and applications will open March 5th.
An ETA costs £10 and permits multiple journeys to the UK for stays of up to 6 months at a time over 2 years. You can download the UK ETA app to apply.
More information about the application can be found HERE.