"(1)Where a person, whether charged with an offence or not, is brought before any court otherwise than for the purpose of giving evidence, and it appears to the court that he is a child or young person, the court shall make due inquiry as to the age of that person, and for that purpose shall take such evidence as may be forthcoming at the hearing of the case, but an order or judgment of the court shall not be invalidated by any subsequent proof that the age of that person has not been correctly stated to the court, and the age presumed or declared by the court to be the age of the person so brought before it shall, for the purposes of this Act, be deemed to be the true age of that person, and, where it appears to the court that the person so brought before it has attained the age of eighteen years, that person shall for the purposes of this Act be deemed not to be a child or young person."
"9. To quote again Ward LJ in A and M [R (on the application of M) v Lambeth LBC[2008] EWCA Civ 1445 ], age determination is often a very difficult question of fact which requires a measure of professional knowledge or experience in the decision maker (see paragraph 81). Thus training is important, as of course is experience in dealing with the issue. The social workers involved in the decision making process who are employed by the local authorities in these cases have had training and do have substantial experience in assessing the age of UASCs. That is the evidence before me and I have no reason to doubt it. That does not of course mean that their decisions are not challengeable, but it does mean that the court should not readily take the view that they are flawed. Since there is no scientific proof available and the final decision involves the exercise of a judgment, it is never possible to be sure that the decision in a given case, particularly where an individual is close to 18, is factually correct. But perfection is unattainable and the approach adopted by the Secretary of State that, if the decision maker is left in doubt, the claimant should receive the benefit of that doubt is undoubtedly proper. But the decision is to be made by the authority not by anyone else ... "