Calculation and making of deduction or repayment
14.—(1) Except where these Regulations otherwise provide, the employer shall ascertain, on the occasion of any payment of emoluments to the employee,—
(a)the cumulative emoluments of the employee at the date of the payment,
(b)the cumulative free emoluments or, as the case may be, the cumulative additional pay,
(c)the cumulative taxable emoluments, and
(d)the cumulative tax.
(2) If the cumulative tax together with any tax not deducted when the last preceding payment of emoluments was made exceeds the previous cumulative tax—
(a)the employer shall deduct the excess from the emoluments on making the payment in question, but
(b)the deduction shall not exceed the overriding limit.
(3) If the cumulative tax together with any tax not deducted when the last preceding payment of emoluments was made is less than the previous cumulative tax, and subject to regulation 36, the employer shall repay the difference to the employee on making the payment in question.
(4) If the cumulative tax together with any tax not deducted when the last preceding payment of emoluments was made is equal to the previous cumulative tax, no tax shall be either deducted or repaid when the payment in question is made.