If any PAYE income of an employee is provided in the form of a readily convertible asset, the employer is to be treated, for the purposes of PAYE regulations, as making a payment of that income of an amount equal to the amount given by subsection (2).

The amount referred to is the amount which, on the basis of the best estimate that can reasonably be made, is the amount of income likely to be PAYE income in respect of the provision of the asset.