HMRC Tax, interest and penalty calculator

If your tax affairs are relatively straightforward - for example, you are only entitled to basic personal allowances - you can use the HMRC calculator to work out your Income tax, Class 4 National Insurance contributions, and any interest and penalties due for tax years ended 5 April 2010 to 5 April 2023 inclusively.

Do you need to file a tax return?

You must send a tax return if, in the last tax year, you were:

• self-employed and earned more than £1,000
• a partner in a business partnership

You may also need to file a tax return if you have other income, such as:

• money from renting out a property
• tips and commission
• income from savings, investments and dividends
• foreign income

Tax deadlines

For the tax year 6 April 2023 to 5 April 2024:

• paper tax returns 31 October 2024
• online tax returns 31 January 2025
• payment of tax owed 31 January 2025