Self Assessment tax calculator

You’ll need to complete a Self Assessment tax return if any of the following criteria apply to you:

• You earn over £1,000 during the tax year through any self-employment venture
• You are a registered sole trader or run your own business
• You have earned over £1,000 during the tax year in your capacity as a corporate partner
• You earn an annual income surpassing £150,000, employed or self-employed
• You earn over £2,500 during the tax year from rental income
• You have any untaxed income over £2,500 earned during the tax year
• Capital Gains Tax Obligations: You have capital gains tax to pay
• You claim child benefit whilst being a high earner
• You are a trustee of a trust or beneficiary of a registered pension scheme
• State Pension is your sole income, and it exceeds the personal allowance
• You have received a P800 notification from HMRC indicating that you didn't pay enough tax the previous year
• You are the director of a limited company, depending on how you receive your income and whether you are already taxed through PAYE

Learn more about completing a Self Assessment here.

Income tax rates for the self-employed are the same as the rates for people employed by a company and paid a salary through payroll. If you’re self-employed, you can claim tax relief on allowable expenses, meaning you will only pay tax on your profit as a sole trader or small business. 

Learn more about self-employed allowable expenses here.

When you complete your Self Assessment, you’ll be given an 11-digit payment reference number, which is typically your Unique Taxpayer Reference (UTR) with the letter K added. 

You can then pay by card, bank transfer, direct debit, through your bank or building society, by cheque, or through your tax code if the amount payable is less than £3,000. You can choose to pay the amount at once or in instalments. 

Learn more about paying your Self Assessment tax here. The deadline for paying your Self Assessment tax is January 31st.