Yes, it is meant to be a voluntary process. However, what practitioners all over the country are telling us is that, in reality, families have to agree to the process if they want access to services.
It's also worth remembering that some LAs are quite wrongly saying that 12-yos can be presumed competent to consent to the CAF. We've just finished a lengthy review of the law relating to children's consent, and there is absolutely no basis in English law for this assertion. The full report can be downloaded from our site:http://www.archrights.org.uk/issues/Virtual%20Child.htm