This Practice Note considers the regulation of influencer activity and what measures exist to protect influencers from online harms. This Practice Note primarily considers UK regulation and measures, but also deals with how UK-based influencers might be subject to EU regulation. It includes consideration of: the UK Code of Non-broadcast Advertising and Direct & Promotional Marketing (CAP Code), UK Code of Broadcast Advertising (BCAP Code), and Part 4 of the Digital Markets, Competition and Consumers Act 2024. It also deals with the regulatory obligations which may be imposed on UK platforms and affect influencers as part of the Online Safety Act 2023, as well as the circumstances in which Regulation (EU) 2022/2065, the EU Digital Services Act may apply to the activity of a UK-based influencer. Finally, this Practice Note also considers how influencers may take practical steps to protect their individual ‘brand’ as this is built up through their influencer activity.