Even if one may believe that .eu domains are not really of great importance, their distribution in Europe was quite high with 3-4 million registered addresses. For British citizens or British companies (and thus for example also a company that trades as a Limited), however, the right to use after the Brexit falls away. According to the current statement of the responsible registrar, domains with Whois address in the UK will become inactive on May 30, 2019.
The domains can be reactivated for up to one year, after which they are put back on the free market. Even if the domain is only used for forwarding to another domain and, for whatever reason, British WHOIS data has been deposited there, this could lead to unpleasant effects of free riders or domain traders, who then have to be laboriously eliminated with the help of trademark law.
Incidentally, this also affects companies based in UK associated territories such as Gibraltar.
