Self-employed individuals are liable to pay both Class 2 and Class 4 National Insurance. For 2019/20, the Class 2 rate is £3 per week where annual profits are in excess of £6,365.
For 2019/20 Class 4 national insurance is payable where annual profits exceed £8,632. Class 4 national insurance is payable on profits exceeding £8,632 at a rate of 9% until profits reach £50,000. Any profits in excess of £50,000 attract Class 4 National Insurance at a reduced rate of 2%.
Here are two examples showing how Class 2 and Class 4 contributions are calculated depending on the annual profits.