ASA overview
The Advertising Standards Authority (ASA) is the UK’s independent advertising regulator.

The ASA is the UK’s independent advertising regulator. It responds to complaints from consumers and businesses and takes action to ban ads across UK media which are misleading, harmful, offensive or irresponsible, in breach of the Codes written by their sister organisation the Committees of Advertising Practice (CAP).
ASA powers of enforcement
Most influencers follow ASA rulings. For those who don't, rather than punish them, the ASA aims to work with them to help them stick to the Advertising Codes. However, for the small minority of influencers who are either unable or unwilling to work with the ASA, some of the sanctions at our disposal can have negative consequences.
One of the ASA's most persuasive sanctions is bad publicity – an advertiser’s reputation can be badly damaged if it is seen to be ignoring the rules designed to protect consumers.