Are you self-employed? Or are you a partner in a trading partnership? If you are, you should be aware of the proposed changes to the accounting period for unincorporated businesses.


HM Revenue & Customs (HMRC) is proposing to change the way that unincorporated businesses are taxed, moving from a ‘current year’ basis to a ‘tax year’ basis. For affected businesses (those that don’t have a year-end between 31 March and 5 April), this could mean a much larger tax bill for the 2022/23 tax year.


So, when are these proposed changes coming in? And what will the potential impact be for sole traders and partners?


What does a change in the base period mean?


Self-employed people and partners in trading partnerships generally prepare accounts to the same fixed date each year. This is known as the ‘basis period’. For tax purposes, profits are currently taxed in the tax year in which the basis period ends.


  • For example, if your business has a 30 June period end, profits for the year to 30/06/2021 would be taxed in the 2021/22 tax year ending 5 April 2022. The tax would then be payable by January 2023.
  • From the 2023/24 tax year, all business will be taxed on a tax-year basis (with 31 March to 5 April being treated as coterminous with the tax year-end). This means that they will pay tax for the 2023/24 year on profits earned in that year.
  • Why is that important? In effect, it means that all self-employed businesses and partners with any other year-end will be required to pay tax earlier than they would previously have done. And this could have a serious impact on tax planning and cashflow!
  • The 2022/23 tax year is proposed as a transitional year in which all affected businesses will be taxed on the profits for their basis period as now, PLUS the tax on their profits from the end of that basis period up to 31 March/5 April 2023.
  • Let’s take a 30th June business as an example. In the 2022/23 tax year you will be taxed on profits from 01/07/2021 to 31/03/2023. So, effectively, you’ll be taxed for 21 months instead of 12. The extra profits may be able to be spread, but the change in base period will result in taxes being paid earlier than they are now.
  • Some of these businesses will have overlap profits carried forward in their tax returns. This will represent profits which were considered to have been taxed twice in their earlier years. That overlap profit can be deducted from the combined amounts being taxed in 2022/23. Any further additional taxable profits may be spread over up to five years, to reduce the impact.
  • The change to the base period will simplify reporting requirements as the Making Tax Digital for Income Tax Self-Assessment (MTD ITSA) changes are rolled out. This change to the base period brings all other forms of income for individuals into account on a tax-year basis, making the whole process easier to administrate.


Talk to us about the proposed changes to your accounting period-end


If the year-end for your business is not currently between 31 March and 5 April, you will potentially be taxed on more than a year’s profits in 2022/23.


Even with a facility to spread the excess, your tax bill will be higher and you could be forced into a higher marginal rate of tax – with all the negative impacts on your tax liabilities. This could be a very serious outcome if you’re not prepared for the changes.


For affected businesses, we can help you prepare forecasts of the likely impact, and consider ways to ease the transition. The earlier you begin planning, the smoother the transition will be.


Talk to us about the impact of the base period changes.



✨Shaking up the accounting profession ✨Business coach ✨Book Author ✨ Multi business-owning mom & wife.

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Madeleine Salariu