NIM24600 - Class 4 NICs: computation of liability: summary

Section 15 of the Social Security Contributions and Benefits Act 1992

The following sections look at the computation of the Class 4 NICs profits.

The self-employed pay Class 4 NICs on profits immediately derived from the carrying on of a trade, profession or vocation (SSCBA92/S15) but only where those profits are chargeable to Income Tax under Chapter 2 of Part 2 to the Income Tax Trading and Other Income Act 2005 (ITTOIA). 

See NIM20725 and NIM70700 for information on Deferment.