Alasdair Taylor's Answer

In general terms, you do not usually need permission to publish a review of the products or services of a business or company, whether online or offline.

However, you do need to be careful with this sort of site.  There are various areas of law that may intrude.  The most obvious are the law of defamation, data protection law and the law of privacy.

• unpleasant or negative reviews may give rise to a right to sue for defamation or malicious falsehood;
• if you are publishing personal data, you need to ensure you comply with the Data Protection Act and in some circumstances this may entail getting consent;
• if you are publishing private or confidential information, there may be a right to bring proceedings for infringement of the right to a private life or breach of confidence.

Both the author of the relevant review, and the website publishing the material, may be targets in these kinds of action.  There are however special defences under the Defamation Act 1996 and the Ecommerce Regulations that can limit the exposure of the publisher.  The extent to which the defences are available depends somewhat upon the nature and design of the site. 

You should therefore take advice from an appropriately qualified lawyer before the site design is finalised.