NIM37010 | Refunds: Class 1: Annual maximum
From HM Revenue & Customs · National Insurance Manual
Regulation 21 of the Social Security (Contributions) Regulations 2001 (SSCR 2001) (SI 2001 No 1004)
There is no annual limit for NICs paid by employers but there is an annual maximum amount of Class 1 and Class 2 contributions payable by contributors. For tax years:
from 2003/2004 onwards, the limit is calculated by reference to a mathematical formula which is provided in regulation 21 of the regulations.