The ASA is the UK's independent regulator of advertising across all media, including marketing on websites. We work to ensure ads are legal, decent, honest and truthful by applying the Advertising Codes.

The Advertising Codes contain wide-ranging rules designed to ensure that advertising does not mislead, harm or offend. Ads must also be socially responsible and prepared in line with the principles of fair competition. These broad principles apply regardless of the product being advertised.

In addition, the Codes contain specific rules for certain products and marketing techniques. These include rules for alcoholic drinks, health and beauty claims, children, medicines, financial products, environmental claims, gambling, direct marketing and prize promotions. These rules add an extra layer of consumer protection on top of consumer protection law and aim to ensure that UK advertising is responsible.

The ASA administers the rules in the spirit as well as the letter, making it almost impossible for advertisers to find loopholes or ‘get off on a technicality’. This common sense approach takes into account the nature of the product being advertised, the media used, and the audience being targeted.

http://www.asa.org.uk/Advertising-Codes.aspx