Section 149

(1) For the purposes of Chapter Six of this Act, the value of taxable
taxable supplies shall be determined as follows, where the supply is –
supplies
(a) for a money consideration, its value shall be the amount which with
the addition of the VAT chargeable is equal to the consideration; and
(b) not for a money consideration, the value of the supply shall be its
market value.
(2) Where a taxable supply is not the only transaction to which a
consideration relates, the supply shall be the part of the consideration as is
properly attributable to it.
(3) For the purposes of Chapter Six of this Act, the market value of a
taxable supply, where it is not for money consideration, or for a supply between
connected persons, shall be the money consideration as may be payable by a
person in a transaction at arm's length.