165Deduction for payments for private use
(1)A deduction is to be made from the provisional sum calculated under step 6 of section 161(1) or step 3 of section 164(2) if, as a condition of the van or vans involved being available for the employee’s private use, the employee—
(a)is required in the tax year in question to pay (whether by way of deduction from earnings or otherwise) an amount of money for that use, and
(b)makes such payment.
(2)If the relevant sum in respect of that year is equal to or exceeds the provisional sum, the provisional sum is reduced so that the value of shared availability is nil.
(3)In any other case the relevant sum in respect of the year is deducted from the provisional sum in order to give the value of shared availability.
(4)The relevant sum is found by—
(a)taking for any van involved the amount paid by the employee as a condition of it being available for the employee’s private use in respect of the period when it is a shared van in the year concerned, and
(b)where more than one van is involved, adding together all the amounts found under paragraph (a).
(5)In this section any reference to a van being available for the employee’s private use includes a reference to the van being available for the private use of a member of the employee’s family or household.