“9C(2) If the officer forms the opinion – (a) that the amount stated in the self-assessment contained in the return as the amount of tax payable is insufficient, and (b) that unless the assessment is immediately amended, there is likely to be a loss of tax to the Crown, he may by notice to the taxpayer amend the assessment to make good the deficiency.”
“31(1) An appeal may be brought against – (a) any amendment of a self-assessment under s 9C of this Act (amendment by Revenue during enquiry to prevent loss of tax), … 31(2) If an appeal under sub-section (1)(a) above against an amendment of a self-assessment is made while an enquiry is in progress none of the steps mentioned in s 49A(2)(a) to (c) may be taken in relation to the appeal until the enquiry is completed.”
“49A(1) This section applies if notice of appeal has been given to HMRC. 49A(2) In such a case – (a) the appellant may notify HMRC that the appellant requires HMRC to review the matter in question (see s 49B), (b) HMRC may notify the appellant of an offer to review the matter in question (see s 49C), or (c) the appellant may notify the appeal to the Tribunal (see s 49D).”
“8(2) The Tribunal must strike out the whole or part of the proceedings if the Tribunal – (a) does not have jurisdiction in relation to the proceedings or that part of them;”