The Advertising Standards Authority (ASA) regulates UK advertising across all media. The system is a mixture of self-regulation for non-broadcast advertising and co-regulation for broadcast advertising (with Ofcom).
All non-broadcast advertising e.g. bill board posters, online advertisements, should comply with the 'Code of Non-broadcast Advertising, Sales Promotion and Direct Marketing' (the 'CAP Code'). A breach of the CAP Code can in the most serious cases result in the mandatory pre-vetting of all Channel 4 off-air marketing for up to 2 years.
All broadcast advertisements (including teleshopping, television text and interactive television advertisements) and programme sponsorship credits on television services licensed by Ofcom should comply with the 'UK Code of Broadcast Advertising' (the 'BCAP Code'). Ofcom retains direct responsibility under the BCAP Code for sponsorship, product placement and participation TV advertising.
Persistent breaches of the BCAP Code can result in the ASA referring the broadcaster to Ofcom, which can then impose a range of statutory sanctions against Channel 4.