Guidance

Get Help with Basis Period Reform

How to get help with changes to Self Assessment for sole traders and partners whose accounting year does not end on or between 31 March to 5 April.

There’s a wide range of online information and tools available to help you get the answers and information you need for the changes in Basis Period Reform.

Using HMRC’s online services are usually much quicker, easier and cheaper than calling us.

Find out how to get help from HMRC if you need extra support.

Watch videos and webinars on Basis Period Reform

Watch a YouTube video to learn about changes to Self Assessment for sole traders and partners whose accounting year does not end on or between 31 March to 5 April.

Get help with basis period reform (moving to the new tax year basis)

Watch a recorded webinar on Basis Period Reform

Check HMRC email updates and webinars for tax agents and advisers to find out about:

  • the new tax year basis
  • the basis period reform transition year
  • overlap relief for the businesses that are affected

For more information on Self Assessment including registration, tax returns, tax bills and payments, read about HMRC email updates, videos and webinars for Self Assessment.

Get more information on Basis Period Reform

For more information on Basis Period Reform and to see if you are affected, read about the changes to reporting income from self employment and partnerships.

You can also read more about how to calculate your taxable profits in the Self Assessment helpsheet HS222.

Get Help with your Overlap Relief Figure

If your business has generated any overlap relief, your final year to claim this will be on your 2023 to 2024 tax return. Find out how to get your Overlap Relief figure.

Use online tools

Work out your transition profit — use this tool to work out your transition profits and help complete your tax return.

Get the HMRC app

You can download the HMRC app onto a mobile device (for example, your phone or tablet) and use it to:

  • check how much Self Assessment tax you owe
  • make a payment
  • set a reminder to make a Self Assessment payment
  • find your Unique Taxpayer Reference (UTR) for Self Assessment
  • update your postal address
  • choose to be contacted by HMRC electronically, instead of by letter
  • track forms and letters you have sent to us
  • claim refunds

Updates to this page

Published 19 February 2024
Last updated 22 May 2024 + show all updates
  1. A link to Self Assessment helpsheet HS222 has been added to the 'Get more information on Basis Period Reform' section of this page.

  2. A link for more information on Self Assessment has been added.

  3. First published.

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