For owners of EU trade marks, if the renewal date is after 1 January 2021, then even if it is renewed at EUIPO prior to the renewal deadline, the UK mark which will be created automatically on 1 January 2021 will still need to be renewed and the UK renewal fee paid in addition to the EU renewal fee.  One silver lining is that the UK renewal deadline will be extended. 

After the UK registration has been created, the UKIPO will notify the owner or representative of the need for renewal and the renewal date will be extended for 6 months from the date of their renewal letter.