In computing the disposable income of the person concerned there shall be deducted the total amount of tax which it is estimated would be payable by the person concerned if that person’s income, as computed in accordance with the foregoing rules of this Schedule (but without taking into account the operation of regulation 11(1) of these Regulations), were that person’s income for a fiscal year and that person’s liability for tax in that year were to be ascertained by reference to that income and not by reference to that person’s income in any other year or period.

For the purposes of this rule the tax shall be estimated at the rate provided by and after making all appropriate allowances, deductions or reliefs in accordance with the provisions of the Income Tax Acts in force for the fiscal year current at the date of the application.