Prove you have right of abode in the UK
Having right of abode means you are allowed to live or work in the UK without any immigration restrictions, which means:
you will not need a visa to come to the UK
there is no limit on the length of time you can spend in the country
All British citizens automatically have right of abode in the UK.
Some Commonwealth citizens may also have right of abode.
You can prove you have right of abode if you have a UK passport describing you as a British citizen or British subject with right of abode.
Otherwise you need to apply for a certificate of entitlement.
There will be no change to the rights and status of EU citizens currently living in the UK until 30 June 2021. You and your family can apply to the EU Settlement Scheme to continue living in the UK.
Further information on the right to reside can be found on GOV.UK's website.