Hi,
The UK tax year starts on 6 April each year.
You are tax resident for the tax year starting 6 April 2024.
You will be UK tax non resident for the tax year 2023 to 2024.
Your partner will need to register for Self Assessment as self employed in tax year 2024 to 2025, if her gross turnover exceeds £1000 in the tax year. Your partner can register as self employed here:
Check how to register for Self Assessment
Thank you.