"16. The issuing of a closure notice is a significant event. It closes the enquiry and requires the Commissioners' officer concerned to state his conclusions and, where those conclusions so require, to amend the taxpayer's tax return to give effect to those conclusions. Only then will the taxpayer be able to make any appeal to the tribunal for determination of any matters disputed between the taxpayer and the Commissioners (such matters having been crystallised in the conclusions in the closure notice and the amendments to the return). The scope of any such appeal is shaped and limited by the terms of the closure notice: as Henderson J expressed it in the Tower MCashback case (at [128]), "
"If there is a moral to be drawn, it is that HMRC should ensure that they have considered all the points on which they may wish to rely before a closure notice is issued."" 19. The provisions of section 28B TMA 1970 are (as with the corresponding provisions relating to companies discussed in the case of HMRC v Vodafone 2[2006] STC 483 at [44]) "constructed so as to produce a reasonable balance", given these different interests of the Commissioners and the taxpayer. It is implicit in the powers given to the General or Special Commissioners to give a direction requiring the issue of a closure notice, and is part of that "reasonable balance", that a closure notice can be required notwithstanding that the officer has not pursued to the end every line of enquiry or investigation – what is required is that he should have conducted his enquiry to a point where it is reasonable for him to make an informed judgment as to the matter in question, so that, exercising such judgment, he can state his conclusions and make any related amendments to the taxpayer's return. The exercise of that judgment may require the officer to express his conclusions in broad terms, or even express alternative conclusions (see the observations made in the case of D'Arcy v HMRC [2006] UKSPC 549 at [12]) – which should at the practical level allow an officer of the Commissioners to avoid the pitfalls identified in the Tower MCashback case of a closure notice too restrictively drafted in its conclusions."