If you've got a .eu domain and it isn't registered in an EU country, which the UK will stop being after Brexit, you will lose it without refund. Migrate NOW.
"As of 30 May 2019, 00:00:00 CEST, all registrants who did not demonstrate their eligibility will be deemed ineligible and their domain names will be WITHDRAWN. A WITHDRAWN domain name no longer functions, as the domain name is removed from the zone file and can no longer support any active services (such as websites or email) but the record will remain in the .eu registry database, and may be reactivated if the eligibility criteria are satisfied." https://eurid.eu/en/register-a-eu-domain/brexit-notice/