From 2024/25 tax year onwards a sole trader is taxed on the profits arising in the tax year. For the transitional rules applying in the tax year 2023/24 which bridges the period between the end of the old basis period rules for 2022/23 and the start of the tax year basis in 2024/25, see the Basis period transitional rules 2023/24. For details of the previous rules on basis periods see the following guidance notes:

1. •

   Basis period (old rules) ― opening years

2. •

   Basis period (old rules) ― normal years

3. •

   Basis period (old rules) ― closing years

4. •

   Basis period (old rules) ― change of accounting date

The old rules for basis periods still applied to businesses that ceased in 2023/24. Where the trader starts to carry on a business, either as a sole trader or as a partner in a partnership, in the tax year 2023/24 (the transitional tax year for the basis reforms) and they do not stop trading in 2023/24, the basis period for 2023/24 starts on the date of