‘6. At [93] and [94] of the Decision, the FTT correctly set out the principles to be derived from the cases on “best judgment” assessments as follows: “93. It is a well-established principle following Van Boeckel that an assessment is made to best judgement if HMRC “fairly consider all material placed before them and, on that material, come to a decision which is one which is reasonable and not arbitrary as to the amount of tax which is due.” Van Boeckel also endorsed the concept that the officer making the assessment: “must not act dishonestly, or vindictively or capriciously, because he must exercise judgement in the matter. He must make what he honestly believes to be a fair estimate of the proper figure of the assessment, and for this purpose he must, their Lordships think, be able to take into consideration local knowledge and repute in regard to the assessee’s circumstances, and his own knowledge of previous returns by and assessments of the assessee, and all other matters which he thinks will assist him in arriving at a fair and proper estimate; and though there must necessarily be guesswork in the matter, it must be honest guess work.” 94. Once this threshold is passed, the burden falls on the taxpayer to establish on the balance of probabilities that the assessment is excessive. In Tynewydd Labour Working Men’s Club and Institute Limited v Customs and Excise Commissioners[1979] STC 570 it was stated that: “… any taxpayer who appeals to the tribunal takes upon himself the burden of proving the assertion he makes, namely that the assessment is wrong, because unless he proves this there is nothing on which the tribunal can find an error in the assessment. There should be no difficulty in the way of the Appellant assuming this burden. The facts and figures are known to him, and if he does not understand the Commissioners’ case, the rules provide for the Commissioners to give a proper explanation.”” 7. Thus, it can be seen that the case law establishes that there are two distinct questions for a tribunal in considering an appeal in respect of a best judgment assessment. The first is whether HMRC have assessed the amount of VAT due “to the best of their judgment”. The second is whether the tribunal has grounds for changing the quantum of the assessment.’
“I have referred to the judgment [of Woolf J] in some detail, because there are dangers in taking Woolf J's analysis of the concept of "best judgment" out of context. The passages I have underlined show that the Tribunal should not treat an assessment as invalid merely because they disagree as to how the judgment should have been exercised. A much stronger finding is required: for example, that the assessment has been reached "dishonestly or vindictively or capriciously"; or is a "spurious estimate or guess in which all elements of judgment are missing"; or is "wholly unreasonable". In substance those tests are indistinguishable from the familiar Wednesbury principles […] Short of such a finding, there is no justification for setting aside the assessment.”