It was announced on the UK Home Office Twitter account
If any EU citizens wish to remain living in the UK after 31 December 2020, then they will need to apply for the need to apply to the EU Settlement Scheme.
As per the official statement on the UK Government’s website:
“If you’re an EU citizen, you and your family will be able to apply to the EU Settlement Scheme to continue living in the UK after 30 June 2021. If your application is successful, you’ll get either settled or pre-settled status.”
There are some examples of being able to stay in the UK without needing to apply for this scheme: if you are an Irish citizen, or have indefinite need to remain. The UK has reached an agreement with Norway, Iceland, Liechtenstein, which you can find here, and a separate agreement with Switzerland, which you can read about here.
The EU Settlement Scheme will be fully open from 30 March 2019, with final applications being accepted on 30 June 2021.
If you have family members from outside either the UK or Ireland, then they will still need to apply even if you do not need to, and you will also still need to apply even if you’re married to a British citizen.
The website explains the new scheme and includes a full breakdown on who should apply, your rights and status, when to apply, if you have permanent residence or indefinite leave to remain, your settled status if you’re under 21, if you stop work early or start work in another EU country, and full details on applying to the EU Settlement Scheme.
You can find all of those details right here.