“(1) Subject to the following provisions of this section, “input tax”, in relation to a taxable person, means the following tax, that is to say - (a) VAT on the supply to him of any goods or services; (b) VAT on the acquisition by him from another member State of any goods; and (c) VAT paid or payable by him on the importation of any goods from a place outside the member States; being (in each case) goods or service used or to be used for the purpose of any business carried on or to be carried on by him.”
“26. Input tax allowable under section 25 (1) The amount of input tax for which a taxable person is entitled to credit at the end of any period shall be so much of the input tax for the period (that is input tax on supplies, acquisitions and importations in the period) as is allowable by or under regulations as being attributable to supplies within subsection (2) below. (2) The supplies within this subsection are the following supplies made or to be made by the taxable person in the course or furtherance of his business – (a) taxable suppliers; … (3) The Commissioners shall make regulations for securing for securing a fair and reasonable attribution of input tax to supplies within subsection (2) above, and any such regulations may provide for – (a) determining a proportion by reference to which input tax for any prescribed accounting period is to be provisionally attributed to those supplies; (b) adjusting, in accordance with a proportion determined in like manner for any longer period comprising two or more prescribed accounting periods or parts thereof, the provisional attribution for any of those periods;”