The UKCA marking applies to most goods previously subject to the CE marking. It also applies to aerosol products that previously required the ‘reverse epsilon’ marking.
The technical requirements (‘essential requirements’) you must meet – and the conformity assessment processes and standards that can be used to demonstrate conformity – are largely the same as they were for the CE marking.
The circumstances in which you can use self-declaration of conformity for UKCA marking are the same as for CE marking. If you were able to self-declare conformity for the CE marking, you will be able to do the same for the UKCA marking.
When will be UKCA Marking be effective?
The UKCA marking came into effect on 1 January 2021. However, to allow businesses time to adjust to the new requirements, you will still be able to use the CE marking until 1 January 2022 in most cases.
The CE marking is only valid in Great Britain for areas where GB and EU rules remain the same. If the EU changes its rules and you CE mark your product on the basis of those new rules you will not be able to use the CE marking to sell in Great Britain, even before 31 December 2021.
When to use UKCA Marking?
You only need to use the new UKCA marking before 1 January 2022 if all of the following apply. Your product:
This does not apply to existing stock, for example if your good was fully manufactured, CE marked and ready to place on the market before 1 January 2021. In these cases, your good can still be sold in Great Britain with a CE marking even if covered by a certificate of conformity issued by a UK body before 1 January 2021. These goods will need to be placed on the market before 31 December 2021.
Above content quoted from UK goverment.
Shenzhen Top Power Co Ltd is involved into applying UKCA certificates for power adapters,it allows the power supplies can be sold in UK from 2022.