The residence status of UK citizens and their family members who use their right to free movement until December 31, 2020 and stay in Slovakia will be modified.
The change is a response to the situation when the Brexit transition period ends.

Slovakia has decided to use the declaratory system for British nationals resident in the country, meaning that UK nationals and their family members who registered with the Foreigners’ Police before January 1, 2021 are not required to apply for a new residential status. They only need to ask for new residence documents by June 30, 2021.
The UK nationals who will not ask for a residence permit before December 31, 2020 will be able to do so anytime in the future. However, they will have to prove they are entitled to do so.
The family members who will want to join UK nationals after January 1, 2021 will have to prove their relationship to the UK national and that it existed even before the end of the transition period. This condition does not apply to children.

This stems from an amendment to the law on the residence of foreigners, which will come into force on January 1, 2021, approved by the parliament on December 8. The change was discussed in a fast-tracked proceeding and approved by 143 MPs present, the SITA newswire reported.
The amendment will enable the UK nationals and their family members, who had been living in Slovakia for more than five years and were registered as EU nationals, to be granted an unlimited permanent residence permit. The UK nationals and their family members who had been living in Slovakia for less than five years will be granted the permanent residence permit for five years.