If you plan to arrive in the UK from today onwards you will (with a few exceptions) need to complete a form with information about when and how you will be arriving and where you will be staying for the first 14 days. This applies to UK residents as well as visitors to the UK.
This is the link to the form which must be completed in advance of your journey and which you will need to show when you arrive, either with a printed copy or by showing it on your phone.
Everyone should complete their own form unless you are arriving with a child under 18 years old who will be arriving and leaving with you and staying at the same address as you in which case you can include their details on your form.
For more detailed information, please see the section on entering the UK in the updated guidance below.