“(1) The Commissioners (HMRC) may by regulations make provision under which, where a taxable person so elects, the amount of his liability to VAT in respect of his relevant supplies in any prescribed accounting period shall be the appropriate percentage of his relevant turnover for that period. ................................................................... (6) The regulations may (a) provide for the appropriate percentage to be determined by reference to the category of business that a person is expected, on reasonable grounds, to carry on in a particular period .”
“(1) The appropriate percentage to be applied by a flat-rate trader for any prescribed accounting period, or part of a prescribed accounting period (as the case may be), shall be determined in accordance with this regulation and regulations 55JB and 55K. ( 2) For any prescribed accounting period (a) beginning with a relevant date, the appropriate percentage shall be that specified in the Table for the category of business that he is expected, at the relevant date, on reasonable grounds, to carry on in that period.”
“ (1) Where, at a relevant date, a flat-rate trader is expected, on reasonable grounds, to carry on business in more than one category in the period concerned, paragraph (3) below shall apply. …………………………………….. (3) He shall be regarded as being expected, on reasonable grounds, to carry on that category of business which is expected, on reasonable grounds, to be his main business activity in that period. ”
“(1) Subject to sections 83G and 84, an appeal shall lie to the tribunals with respect to any of the following matters …………………….. (fza) a decision of [HMRC] ......................................................... (ii) as to the appropriate percentage or percentages (within the meaning of that section) applicable in a person's case”
“(4 ZA) Where an appeal is brought (a), against such a decision as is mentioned in [section 83(1)(fza)] , or (b) to the extent that it is based on such a decision, against an assessment, the tribunal shall not allow the appeal unless it considers that [HMRC] could not reasonably have been satisfied that there were grounds for the decision.”