If you are self employed you will pay the following taxes:
Income tax
Income tax is paid on your profits.
Profit = Income less allowable costs
Your accounts, which would be used to complete your self assessment, should show how you have arrived at your profits.
National Insurance
One of the reasons for registering as self employed is that you will need to start paying National Insurance in a different way than if you were employed.
As a self employed person you will pay the following National Insurance contributions:
Class 2
If your profits from your self employed business exceed more than £5,965 per year you will pay Class 2 National Insurance at a rate of £2.80 per week. This will be collected via your self assessment tax return.
Note – Class 2 is under review by HMRC and may soon be abolished. As and when things change this will be updated.
Class 4
Class 4 National Insurance is paid if your self employed profits exceed £8,060 per year.
The amount due is 9% on profits between £8,060 and £43,000 and then 2% on profits over £43,000. Class 4 contributions are paid along with your income tax using the Self Assessment tax return.