The latest Guidance published in November 2021 provides information on the following topics:
• Placing goods on the market in Great Britain (page 3)
• Circulation of goods on the market (page 5)
• UKCA labelling easement (page 6)
• Components (page 7)
• Prototypes and testing (page 9)
• Leasing and hiring (page 10)
• Economic operator responsibilities (page 11)

This guidance is intended to apply to goods which require UKCA marking.

https://www.gov.uk/guidance/placing-manufactured-goods-on-the-market-in-great-britain#further-guidance

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1032312/ukca-implementation-guidance.pdf