Navigating the basis reform maze

For guidance on how the transitional profit is calculated please see our previous articles:

• Basis period reforms – handling the transition
• The looming abolition of basis period for sole traders and partnerships

For the 2023/24 tax year, businesses affected by basis period reform must complete the full version (SA103F) of the self-employment pages, as the short version (SA103S) lacks the necessary fields to report transition profits.

For businesses that started before 6 April 2023 and did not cease in the year:

• Box 66 (basis period start date): This the day after the basis period for 2022/23 ended. For example, if in 2022/23 the business has prepared the accounts to 31 December 2022, it should enter 1 January 2023
• Box 67 (basis period end date): always 5 April 2024.

For businesses maintaining their existing accounting date:

• report accounting period results in boxes 15-65 (the ‘standard part profits’). Using the December year end that would be from 1 January 2023 to 31 December 2023
• enter total transition profit/loss (before overlap and spreading) in box 73.1 (the ‘transition part profits’). Using the December year end that would be from 1 January 2024 to 5 April 2024
• claim overlap relief in box 73.2
• report spread transition profits for 2023/24 in box 73.3.

For businesses changing their accounting date to 31 March/5 April:

For example, if the business has prepared a long set of accounts from 1 January 2023 to 5 April 2024:

• eport full accounting period results in boxes 15-65 (1 January 2023 to 5 April 2024)
• emove transition profits via negative adjustment in box 68 (1 January 2024 to 5 April 2024)
• bring transition profits back as positive adjustment in box 73.1
• claim overlap relief in box 73.2
• report spread transition profits for 2023/24 in box 73.3.

Remember to use HMRC’s transition profit calculator and helpsheet HS222 for additional guidance on completing these boxes.

Further resources

• Basis period reforms – handling the transition
• Get ready for the 2023/24 basis period transition
• Free webinar: Understanding basis period reform