(1)This section applies if in a tax year a car—
(a)is available to more than one employee concurrently,
(b)is so made available by the same employer, and
(c)is available concurrently for each employee’s private use,
and two or more of those employees are chargeable to tax in respect of the car in that year by virtue of section 120.
(2)The cash equivalent of the benefit of the car to each of those employees for that year—
(a)is to be calculated separately under section 121, and
(b)is then to be reduced on a just and reasonable basis.
(3)If the employment of any of the employees mentioned in subsection (1)(a) is an excluded employment, the availability of the car to that employee is to be disregarded for the purposes of subsection (2)(b).
(4)In this section the reference to the car being available for each 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.