"There is no express requirement that the officer must set out or state the reasons which have led him to his conclusions, and in the absence of an express requirement I can see no basis for implying any obligation to give reasons in the closure notice. What matters at this stage is the conclusion which the officer has reached upon completion of his investigation of the matters in dispute, not the process of reasoning by which he has reached those conclusions."
"There is a venerable principle of tax law to the general effect that there is a public interest in taxpayers paying the correct amount of tax, and it is one of the duties of the Commissioners in exercise of their statutory functions to have regard to that public interest. [The judge then considered changes in the tax system and continued] For present purposes, however, it is enough to say that the principle still has at least some residual vitality in the context of section 50, and if the Commissioners are to fulfil their statutory duty under that section they must in my judgment be free in principle to entertain legal arguments which played no part in reaching the conclusions set out in the closure notice. Subject always to the requirements of fairness and proper case management, such fresh arguments may be advanced by either side, or may be introduced by the Commissioners on their own initiative. That is not to say, however, that an appeal against a closure notice opens the door to a general roving inquiry into the relevant tax return. The scope and subject matter of the appeal will be defined by the conclusions stated in the closure notice and by the amendments (if any) made to the return."
"It seems to me inherent in the appeal system that the tribunal must form its own view on the law without being restricted to what the Revenue state in their conclusion or the taxpayer states in the notice of appeal. It follows that either party can (and in practice frequently does) change their legal arguments. Clearly any such change of argument must not ambush the taxpayer and it is the job of the Commissioners hearing the appeal to prevent this by case management."