Universal Social Charge Regulations 2018 (S.I. No. 510 of 2018)
17. Arrears of pay
(1) This Regulation applies to payments of relevant emoluments made to or on behalf of an employee after he or she has ceased to be employed by the person making the payments.
(2) On making any payment referred to in paragraph (1), an employer shall deduct USC—
(a) in the case of an employee in respect of whom a revenue payroll notification has been sent to or made available to the employer, by reference to the rate cut-off points that would have applied to the payment if the employee was still employed by the employer on the date of payment and Regulation 14 had applied, or
(b) in any other case, in accordance with Regulation 19(1).