There is a ‘proposed’ amendment being circulated that has not yet been voted on by the UK Government (so we cannot say it will happen or not). If the vote passes in late Autumn, the UKCA legislation will be changed once again to allow ‘EU Notified body’ ATEX Certificates (aligning with UK Designated Standards) to be used in lieu of Approved Body certificate in a ‘self-declaration’ for 5 years, or until a variation is required. This also applies to the ATEX QAN (when it expires you will need a UKCA QAN).
You will need the UKCA Declaration of Conformity to UK Designated Standards and the UKCA Marking on your product (but if the proposed is passed a ‘sticker’ may be used for temporary UKCA Ex Marking)
All new products requiring certification must have a UKCA Appointed Body Certificate in 2023 (so only Certificates with an issue date up to December 31st 2022 would be accepted and only until they have a variation or for 5 years, which ever is sooner)
There are obviously major concerns with having two different sets of requirements at the same time with no apparent mechanisms for monitoring or controlling conformity, particularly in the field of explosion prevention. The UKCA Ex Group have raised the problems with the relevant parties. An official post on this will be made on the UKCA EX Approved Bodies Group shortly, this is the only place you should get your official information on UKEX site link below.