Most importantly, nothing has changed as of now. All EU trademarks, including new applications, will include the United Kingdom until the end of the transitional period (which will run until 31 December 2020).
At the end of the transitional period, all EU trademarks that have already been registered will be subject to national UK trademark registration. This is done automatically and requires no action on the part of the trademark holder. If you do not wish to have a national UK registration, you can notify the UK Trademark Office, and have the registration cancelled.
EU trademark applications that are pending at the end of the transitional period will not automatically be converted into national UK applications. However, the applicant is entitled to convert the application into a national UK application. This must be done within nine months of the end of the transitional period. The new national application will retrospectively have the same application date as the EU application. The application will be examined by the UK Trademark Office in accordance with UK and will be subject to a government filing fee.
Let us know if you want to have more information about Brexit’s impact on trademarks.