EUSS processes the registration of nationals of EU and EFTA countries who were resident in the United Kingdom prior to the end of the Brexit transition/implementation period (which followed the technical departure of the UK from the European Union) at 11pm GMT on 31 December 2020 ("IP completion day"[1][2][3]).
The system also extends rights to certain family members who resided with a British citizen in an EU or EFTA country prior to IP completion day.
[5] To complete an application through the online portal, citizens must have a valid passport or national identity card, and may be asked to provide proof of continuous residence if checks with the Department for Work and Pensions and His Majesty's Revenue and Customs cannot confirm the duration of stay using the applicant's National Insurance number.
[7] They are able to remain in the UK as long as they wish, subject to conditions, and retain the same rights to employment, welfare, education and public funds as previously; they may also apply for British citizenship upon meeting particular requirements.
Nationals of EU and EFTA countries who started living in the UK on or before 31 December 2020, but do not have five years' continuous residence at the time they apply, are usually granted pre-settled status.
[10] Time outside the UK totalling six months (180 days) or more within any 12-month period may disqualify an individual from becoming eligible for settled status.
)[11][12] Rights and status of all EU, EEA and Swiss citizens living in the UK remained unchanged until 30 June 2021.