Beta This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Debt Management and Banking Manual

Class 4 NICs: What are Class 4 NICs

Class 4 National Insurance

Class 4 National Insurance Contributions are payable by the self employed on profits between a lower and upper limit, and are collected with tax under a Self Assessment.

Unlike Class 2, Class 4 contributions do not count at all for benefit purposes.