“One must ask oneself: was what the taxpayer did a reasonable thing for a responsible trader conscious of and intending to comply with his obligations regarding tax, but having the experience and other relevant attributes of the taxpayer and placed in the situation that the taxpayer found himself at the relevant time, a reasonable thing to do?... It seems to me that Parliament in passing this legislation must have intended that the question of whether a particular trader had a reasonable excuse should be judged by the standards of reasonableness which one would expect to be exhibited by a taxpayer who had a responsible attitude to his duties as a taxpayer, but who in other respects shared such attributes of the particular appellant as the tribunal considered relevant to the situation being considered. Thus though such a taxpayer would give a reasonable priority to complying with his duties in regard to tax and would conscientiously seek to ensure that his returns were accurate and made timeously, his age and experience, his health or the incidence of some particular difficulty or misfortune and, doubtless, many other facts, may all have a bearing on whether, in acting as he did, he acted reasonably and so had a reasonable excuse.” 29. That this is the correct test was confirmed by the Upper Tribunal in Perrin v HMRC[2018] UKUT 156 . At [81] of that judgment, the Upper Tribunal also set out a recommended process for this Tribunal when considering whether a person has a reasonable excuse : “(1) First, establish what facts the taxpayer asserts give rise to a reasonable excuse (this may include the belief, acts or omissions of the taxpayer or any other person, the taxpayer's own experience or relevant attributes, the situation of the taxpayer at any relevant time and any other relevant external facts). (2) Second, decide which of those facts are proven. (3) Third, decide whether, viewed objectively, those proven facts do indeed amount to an objectively reasonable excuse for the default….In doing so, the Tribunal should take into account the experience and other relevant attributes of the taxpayer and the situation in which the taxpayer found himself at the relevant time or times. It might assist the Tribunal, in this context, to ask itself the question “was what the taxpayer did (or omitted to do or believed) objectively reasonable for this taxpayer in those circumstances?” (4) Fourth, having decided when any reasonable excuse ceased, decide whether the taxpayer remedied the failure without reasonable delay after that time (unless, exceptionally, the failure was remedied before the reasonable excuse ceased). In doing so, the FTT should again decide the matter objectively, but taking into account the experience and other relevant attributes of the taxpayer and the situation in which the taxpayer found himself at the relevant time or times.”
“One situation that can sometimes cause difficulties is when the taxpayer’s asserted reasonable excuse is purely that he/she did not know of the particular requirement that has been shown to have been breached. It is a much-cited aphorism that “ignorance of the law is no excuse”, and on occasion this has been given as a reason why the defence of reasonable excuse cannot be available in such circumstances. We see no basis for this argument. Some requirements of the law are well-known, simple and straightforward but others are much less so. It will be a matter of judgement for the FTT in each case whether it was objectively reasonable for the particular taxpayer, in the circumstances of the case, to have been ignorant of the requirement in question, and for how long.”