There is some updated information about the transitional period of UKCA mark on the gov.uk website. The UKCA marking will apply to most goods currently subject to the CE marking.

The UKCA marking can be used from 1January 2021. However, in order to make enterprises better adjust to the newrequirements, they can still use the CE marking until 1 January 2022 in mostcases.

More information as below link:

https://www.gov.uk/guidance/placing-manufactured-goods-on-the-market-in-great-britain-from-1-january-2021

In some special cases, for example, CE marking can continue to be used and recognized until 30 June 2023 for medical devices.

More information as below link:

https://www.gov.uk/guidance/regulating-medical-devices-from-1-january-2021