“When considering a “reasonable excuse” defence, therefore, in our view the FTT can usefully approach matters in the following way: (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 and the time when that objectively reasonable excuse ceased. In doing so, it should take into account the experience and other relevant attributes of the taxpayer and the situation in which the taxpayer found [themselves] at the relevant time or times. It might assist the FTT, 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?”
“… the test of whether or not there is a reasonable excuse is an objective one. In my judgment it is an objective test in this sense. One must ask oneself: was what the taxpayer did a reasonable thing for a responsible trader conscious of and intending to comply with [their] obligations regarding tax, but having the experience and other relevant attributes of the taxpayer and placed in the situation that the taxpayer found [themselves] in at the relevant time, a reasonable thing to do? Put in another way which does not I think alter the sense of the question: was what the taxpayer did not an unreasonable thing for a trader of the sort I have envisaged, in the position the taxpayer found [themselves], 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 [their] 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 [their] duties in regard to tax and would conscientiously seek to ensure that [their] returns were accurate and made timeously, [their] age and experience, [their] 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 [they] did, [they] acted reasonably and so had a reasonable excuse.”