The European patent system is entirely unaffected by Brexit, as explained here and in the below video.
Update – June 2021
We have created a handy Quick Guide to answer the key questions about Brexit and your intellectual property rights – read it here.
Update – March 2019
We are pleased to announce that, in view of ongoing political uncertainty we have “Brexit-proofed” our business and our clients’ intellectual property portfolios by partnering with German-based patent, design and trade mark attorney firm RGTH (Richter · Gerbaulet · Thielemann · Hofmann Patentanwälte) – http://rgth.de/index.php/en/. This UK-EU alliance will help our clients to seamlessly navigate the potential implications of Brexit whatever the outcome.
Update – December 2018:
In the event of a “no-deal Brexit” (i.e. whereby the UK exist the EU without any agreed transition period), the UK government has published the following technical notice confirming what the impact would be on how the system of registered and unregistered EU trade mark and designs would be affected: https://www.gov.uk/government/publications/trade-marks-and-designs-if-theres-no-brexit-deal/trade-marks-and-designs-if-theres-no-brexit-deal