Closing self assessment

I used a 3rd party service to file a tax return for me as I believed I’d overpaid tax, and it turned out I had. But now I don’t want to continue with self assessment. What do I put as my reason for wishing to close self assessment and the date my circumstances changed? Nothing has changed per se, I just don’t want to continue with self assessment. Thanks

Hi Unaccounted4,
You can check if you still meet Self Assessment criteria here:
Check if you need to send a Self Assessment tax return
And if criteria not met you can submit an online request to close your account.
You can also contact HMRC direct to review and close the Self Assessment record.
Self Assessment: general enquiries
Thank you.