Alasdair Taylor's answer to Parental consent for use of website (312527885)

Answer to the question: 

It may be a good idea to include the age requirement in the T&Cs and in the body of any sign-up page. However, this will not be sufficient for some purposes (e.g. for consent to processing under data protection law).  You should take proper advice on this from a suitable experienced lawyer, as the applicable rules are not always straightforward.