It is unclear whether trademarks registered in the EU would be applicable to the UK in the future.
Your business should consider
Do you own any Intellectual Property rights?
Have you contacted trademark bodies / solicitors / IP advisors on how to protect your intellectual property after March 2019?
Resources and information
UK Government technical notices on intellectual property if there’s no Brexit withdrawal agreement have been published on these topics:
Copyright if there’s no Brexit deal:
Exhaustion of intellectual property rights if there’s no Brexit deal:
Patents if there’s no Brexit deal:
Trade marks and designs if there’s no Brexit deal: