Hi devids1,
You can inform us that your ceasing being Self Employed as a sole trader here:
Stop being self-employed
You can file your 23/24 return immediately, while you can send us your 24/25 return from the 6th of April 2025.
If you have left the country when you file your 24/25 return, please send a paper copy, and include a SA109.
Read more advice here:
Tax if you leave the UK to live abroad
Thank you.