Part 3Employment income: earnings and benefits etc. treated as earnings
Chapter 6Taxable benefits: cars, vans and related benefits
Cars: unavailability or payments for private use
143Deduction for periods when car unavailable
(1)A deduction is to be made from the amount carried forward from step 6 of section 121(1) if the car has been unavailable on any day during the tax year in question.
(2)For the purposes of this section a car is unavailable on any day if the day—
(a)falls before the first day on which the car is available to the employee,
(b)falls after the last day on which the car is available to the employee, or
(c)falls within a period of 30 days or more throughout which the car is not available to the employee.
(3)The amount of the deduction is given by the formula—
where—
U is the number of days in the year on which the car is unavailable,
Y is the number of days in that year, and
A is the amount carried forward from step 6.
(4)This section is subject to section 145 (modification where car temporarily replaced).
144Deduction for payments for private use
(1)A deduction is to be made from the provisional sum calculated under step 7 of section 121(1) if, as a condition of the car 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 amount paid by the employee in respect of that year is equal to or exceeds the provisional sum, the provisional sum is reduced so that the cash equivalent of the benefit of the car for that year is nil.
(3)In any other case the amount paid by the employee in respect of the year is deducted from the provisional sum in order to give the cash equivalent of the benefit of the car for that year.
(4)In this section the reference to the car being available for the employee’s private use includes a reference to the car being available for the private use of a member of the employee’s family or household.
(5)This section is subject to section 145 (modification where car temporarily replaced).
145Modification of provisions where car temporarily replaced
(1)This section applies if—
(a)the car normally available to an employee (“the normal car”) is not available to the employee for a period of less than 30 days,
(b)another car (“the replacement car”) is made available to the employee in order to replace the normal car for the whole or part of that period,
(c)the employee is chargeable to tax in respect of both the normal car and the replacement car by virtue of section 120, and
(d)the replacement car meets condition A or B.
(2)Condition A is met if the replacement car is not materially better than the normal car.
(3)Condition B is met if the replacement car is not made available to the employee under an arrangement of which the main purpose, or one of the main purposes, is to provide the employee with the benefit of a car which is materially better than the normal car.
(4)If this section applies—
(a)section 143 (deduction for periods when car unavailable) applies so that the replacement car is to be treated as unavailable on the days of the period during which it replaces the normal car, and
(b)section 144 (deduction for payments for private use) applies as if the replacement had not been made and the replacement car were a continuation of the normal car.
(5)A replacement car is regarded as materially better than the normal car if—
(a)it is materially better in quality, or
(b)when calculating the cash equivalent of the benefit of the replacement car, the interim sum calculated under step 4 of section 121(1) is materially higher than the interim sum calculated in relation to the normal car.