If you are an EU citizen, resident in the UK by 31 December 2020, you and your family members (including non-EU citizens) need to apply to the EU Settlement Scheme to continue to live, work and study in the UK beyond 30 June 2021.
Even if you have lived in the UK for many years or you have a permanent residence document, you still need to apply. Only settled status confers the right to claim benefits.
You do not need to apply if you have indefinite leave to remain or enter, or you are an Irish citizen, but you can if you want to.
The online application checks your identity and UK residence, and asks you to declare any criminal convictions. The deadline for applications is 30 June 2021.