UK Competition and Markets Authority has published guidelines about hidden advertising on social media

The Competition and Markets Authority (CMA) published resources to enable those involved in creating content, posting it on social media, and sharing promotions to comply with consumer protection law.

Three guides were released for social media platforms, brands, and influencers regarding paying promotions, explaining roles, and responsibilities in the field of online advertising:

Guidance for social media platforms describes the Compliance Principles for social media platforms

Guidance for businesses/brands requires information and supervision of the brands to the influencers

Guidance for influencers determines rules for paid posts as endorsements using #Ad or #Advert and #gift, #gifted, or #spon, among other hashtags.