According to Gov.uk: "You must complete a passenger locator form online before you arrive in the UK. You must complete the form even if you are only transiting through the UK.

You must usually complete a passenger locator form online before you arrive in the UK.

Travellers who have been double-vaccinated no longer need to quarantine on arrival in the UK, but everyone returning must complete a Passenger Locator Form (PLF).

Travellers who have been double-vaccinated no longer need to quarantine on arrival in the UK, but everyone returning must complete a Passenger Locator Form (PLF).

Travellers who have been double-vaccinated no longer need to quarantine on arrival in the UK, but everyone returning must complete a Passenger Locator Form (PLF).

Everyone arriving in the UK has to complete a Passenger Locator Form (Image: Adam Gerrard / Daily Mirror) On arrival, passengers must show the form or a QR code supplied when it is completed.

Everyone arriving in the UK has to complete a Passenger Locator Form (Image: Adam Gerrard / Daily Mirror) On arrival, passengers must show the form or a QR code supplied when it is completed.

Everyone arriving in the UK has to complete a Passenger Locator Form (Image: Adam Gerrard / Daily Mirror) On arrival, passengers must show the form or a QR code supplied when it is completed.

Travellers who have been double-vaccinated no longer need to quarantine on arrival in the UK, but everyone returning must complete a Passenger Locator Form (PLF).