“(1) This regulation applies if a contribution other than a Class 4 contribution has been paid in error. ... (2) If this regulation applies, an application may be made to [HMRC] for the return of the contribution paid in error. ... (4) On the making of an application under paragraph (2) [HMRC] shall return the contribution paid in error. ... (9) In this regulation “error” means, and means only, and error which – (a) is made at the time of the payment; and (b) relates to some past or present matter.” 21 The central question argued before Judge Berner in the tribunal below was whether, as a matter of law or fact, any of the appellants had paid their contributions in error. This was also the central question argued before Richards J in a similar appeal from a decision of the former General Commissioners decided in the Chancery Division in Fenton v HMRC ,17 June 2010 . The decision under appeal 22 Judge Berner decided in the cases of the individual Appellants now before us that as no official announcement had been made at the time when each of them had made their contributions, those contributions could not be said to have been made in error”. 23 The same issue came before Richards J in Fenton. In that case the appellant had been paying additional Class 3 contributions by instalments. It became clear, with the benefit of hindsight, that he need not have paid any of the instalments. HMRC refunded him instalments he had paid after the start of the tax year 2006-2007, but refused to refund earlier instalments on the ground that they had not been paid in error. Richards J agreed that the pre-2006-2007 instalments were not payments in error under regulation 52. That decision is technically not binding on this tribunal but is to be followed unless there is good reason not to do so. 24 We fully agree with the decisions of both Richards J and Judge Berner about the application of regulation 52 to this group of cases. The definition of “error” in regulation 52(9) is wide in terms of the material scope of the term but it is entirely clear about its temporal effect. It can apply only to errors made at the time of payment, and then only to errors about some then present or past matter. A future change of law, as yet unannounced, cannot be the cause of an “error” within that temporal rule. 25 Different considerations arise once the government had announced the prospective change. There is inevitably a period of uncertainty between the initial formal announcement of the prospective change and its formal enactment, and that uncertainty generates scope for error by individuals. In this case that period lasted 18 months. Further, the White Paper was published by the Secretary of State for Work and Pensions and not HMRC, who had the task of collecting the contributions, so there were risks of divided responsibility. It is within that context that the appeal made to the tribunal below by Mr Brumpton is to be viewed. 26 Mr. Forsdick acknowledged that he was advancing his contention in relation to Mr. Brumpton’s case in a slightly different, and narrower, manner before us than he had done before Judge Berner. Before Judge Berner, he had essentially argued that the test as to whether Mr. Brumpton had made his contribution in error was an objective one, that Mr. Brumpton had acknowledged that he had received the flyer, so that he must be judged objectively to have made an informed decision. Judge Berner’s decision in relation to Mr. Brumpton’s case was that his contribution was made in error. Since the proposed rule change was a matter in the public domain, but that he was nevertheless ignorant of it, he did not make a legitimate choice to make his payment at the Post Office. He made the payment on account of a “present error” in relation to a “present matter”, and so was entitled to a refund. 27 Before us, Mr. Forsdick changed his contention in the following way. Referring first to the situation with which we were not strictly concerned, namely the possible case where a person may have received and understood the flyer, but still made a payment, he argued that in that situation the contribution would have been made not “in error”, but as a result of “a deliberate choice”