"the year-end calculation will -- -- work out a total margin achieved; -- apportion the total margin between different types of supplies, that is: a margin scheme, in-house, agency; -- apportion the total margin between supplies with different VAT liabilities, for examples standard-rated, zero-rated or exempt; -- work out the output tax due on margin scheme supplies and packages; and -- work out net values for supplies with different VAT liabilities."
"53(1) The Treasury may by order modify the application of this Act in relation to supplies of goods or services by tour operators or in relation to such of those supplies as may be determined by or under the order."
“TL5 1. Subject to Section TL3 of Section 12 of this Notice, the value of designated travel services, in-house supplies and agency supplies shall be determined by applying the formula set out in Section 8 of this Notice (hereinafter referred to as "the full calculation"), unless during the relevant period all such supplies are liable to VAT at the same rate, in which case the value shall be determined by applying the formula set out in Section 10 of this Notice (hereinafter referred to as "the simplified calculation"). 2. The provisional value of designated travel services, in-house supplies and agency supplies shall be determined in accordance with the formula set out in: (a) Section 9 of this Notice, where the full calculation applies; or (b) Section 11 of this Notice, where the simplified calculation applies. 3. A tour operator shall be required to account for VAT on the provisional value of his supplies of designated travel services, in-house supplies and agency supplies on the VAT return for the prescribed accounting period in which the supplies are made. 4. The difference between the amount of VAT due on the value of designated travel services, in-house supplies and agency supplies supplied during a tour operator’s financial year, and the amount of VAT paid on the provisional value of those supplies, shall be adjusted by the tour operator on the VAT return for the first prescribed accounting period ending after the end of the financial year during which the supplies were made.”
“ 77: time limits and supplementary assessments (1) Subject to the following provisions of this section, an assessment under section 73 … shall not be made -- (a) more than 3 years after the end of the prescribed accounting period… concerned”