Best judgement: what it means
The meaning of the phrase ‘to the best of their judgement’ and principles inherent in HMRC requirement to exercise best judgement were considered in a VAT High Court ruling given by Woolf J, as he was then, in the appeal case Van Boeckel v C & E QB Dec 1980,  STC 290.
The case set the benchmark for best judgement. In summary, the principles adopted in Van Boeckel are that
- HMRC should not be required to do the work of the taxpayer
- HMRC must perform their function honestly and above-board
- HMRC should fairly consider all the material before them and on that material, come to a decision which is reasonable and not arbitrary, and
- there must be some material before HMRC on which they can base their judgement.
The basic principles have been refined in a number of other cases. In the case of CA McCourtie LON/92/191 the tribunal considered the principles set out in Van Boeckel and put forward three further propositions
- the facts should be objectively gathered and intelligently interpreted
- the calculations should be arithmetically sound, and
- any sampling technique should be representative.