Guidance

Help with self-employment on your Self Assessment tax return

Find information on completing the self-employment section of your Self Assessment tax return.

If you’re self-employed, your business will have various running costs. You can deduct some of these costs to work out your taxable profit as long as they’re allowable expenses. You will need to add up all your allowable expenses for the tax year and put the total amount on your Self Assessment tax return.

You can use cash basis to work out your income and expenses for your Self Assessment tax return, if you’re a sole trader or partnership without corporate partners.

You do not need to send in proof of expenses when you submit your tax return. But you should keep proof and records so you can show them to HMRC if asked.

Helpsheets for filling in your tax return

Helpsheets provide information which can help you complete certain sections of your Self Assessment tax return. For example, checking if you qualify for a certain relief and working out figures you might need to include in your return.

More than one business

Find information about your tax return if you have more than one business (HS220).

Agricultural

Read helpsheets to:

Other occupation or role specific

Read helpsheets about:

Other self-employment helpsheets

Read helpsheets about:

HMRC YouTube videos

YouTube playlist on self-employment

Watch a collection of HMRC videos to find out more about self-employment and to help you understand and complete the self-employment section of your tax return.

You will learn about:

  • getting help with basis period reform

  • basic record keeping

  • cash basis and simplified expenses

  • what expenses you can include on your tax return

  • claiming motoring expenses

  • what self-employed expenses are allowable for business premises

  • other allowable business expenses

  • Class 2 National Insurance contributions

Recorded webinar on self-employment

Watch a recorded webinar about the self-employment section of your online tax return.

The self-employment section of your online tax return

You will learn about:

  • business and turnover

  • expenses

  • capital allowances and balancing charges

  • losses

  • tax deducted and Class 4 National Insurance contributions

Paper tax return

If you complete a paper tax return, you may need to use a supplementary page to record self-employment income on your SA100 tax return. You can use either:

Updates to this page

Published 28 May 2025

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