Domestic Diva - try
www.crb.gov.uk for more information, you may need to contact them for information about the agancies (there is a web-site I have used but cannot remember it).
I haven't applied for one and it has never affected my business (in fact staff vetting is incredibly rarely brought up by a potential client) but I only do commercial work so cannot really advise on domestic.
Littlejack - in the context of this thread the two checks are totally different.
The police check we are talking about here is the one where the individual approaches the police and obtains what is fairly basic information about convictions (I think in the last 5 years).
The CRB check is carried out on behalf of the employer and is far more thorough, and I believe that there are different levels depending upon the amount the employer is prepared to pay and the sensitivity of the working environment. For example anyone working with children should have the greatest level of checking and covers aspects over and above criminal activities.
It is the CRB check that teachers, security guards, nursery staff etc are subject to rather than the basic Police check.
It is not a breach of the HR Act to carry out a CRB check, and it is also OK for an individual to volunteer to obtain a police check. However while working for a large cleaning company I remember receiving a memo stating that no longer could the company ASK an individual to obtain this certificate as it was considered a breach of the Act. As I am not 100% sure of it you will notice that I stated that I
understood it to be the case rather than saying it was.
I hope this clarifies everything.