•Liability to NICs depends on the class of contributor into which an individual falls (see ¶12100ff.).

•There are currently six classes of contributions that can be paid – Class 1, Class 1A, Class 1B, Class 2, Class 3 and Class 4 (see ¶12105).

•It is important to establish whether an earner is employed or self-employed to ensure the correct contributions are paid (see ¶12120).

•Certain earners are categorised as employed or self-employed by regulations (see ¶12140ff.).

•Some social security benefits are only paid to individuals with a qualifying contribution record (see ¶12220).