NIM08040 - Earnings Periods: Earnings paid at regular intervals: Occasional changes in pay interval
Regulations 7(1)(a) & 2(a) of the Social Security (Contributions) Regulations 2001 (SSCR 2001) (SI 2001 No 1004)
Occasional changes in the pay interval do not change the earnings period. If on an isolated occasion an employer pays an employee on a day other than their regular pay day, treat the payment as made on the regular pay day and within the earnings period in which that day falls. See also NIM08700 and particularly NIM08720 if the payment spans different tax years.