National Insurance (NI) is a key part of the UK’s social security system. Many people misunderstand it. However, it is vital for access to many state benefits. Whether you are an employee, self-employed, or an employer, understanding NI is key to planning. It also helps ensure you are covered when you need it most. This complete guide explains :
1. What NI is and its main types.
2. Who pays NI and when it is paid.
3. How NI is paid and what it funds.
4. National Insurance on Benefits in Kind (BIK).

