Work back my tax assessment and tax return for the earnings from Hong Kong

I moved to UK from Hong Kong in late August 2021. I am not sure if I need to fill in tax return for the items mentioned below. (1) Do I need to disclose what I have saved/earned from Mandatory Provident Fund (MPF) but I have never cashed out? (2) Do I need to disclose the interests what I have earned from the saving account of the banks in Hong Kong?; (3) Do I need to disclose the interests what I have earned from the shares in Hong Kong but I have never cahsed out? (4) Since I have not filled in any tax return for the previous financial years in UK, how could I work back my tax return, if needed? Thank you.

Hi,
The mandatory provident fund is not taxable in the UK, so does not need to be declared on a self assessment tax return.
The UK / Hong Kong tax treaty allows for the UK to tax interest arising in Hong Kong and paid to a resident of the UK (articel 11).  
It is the same for dividends (article 10).  2010 Hong Kong-UK DTA.
Being in receipt of foreign income, is criteria for completing a self assessment tax return.
 If you have not registered for self assessment, you can do this at Check how to register for Self Assessment.  
If you need to print off tax returns and supplementary pages, you can do this atSelf Assessment tax return forms, which includes links to archived tax returns.
Thank you.

If I have not done the split year treatment for the financial year 2021-22. How can I tell HMRC now?

Hi,
As it is too late to amend your 2021 to 2022 tax return, you will need to submit a SA109 along with a letter advising which income is either included in the return, when it should not be or income that should be in the return, but is not.  
Residence, remittance basis etc (Self Assessment SA109)
We can manually review your tax return and recalculate your liability, raising revenue assessments where you have more to pay.
Thank you.
 

Should I fill in the SA109 for Year 2022 instead of 2024? Will there be any fee/fine to be charged?

Hi,
As the SA109 is for the tax year 2021 to 2022, you will need to use the SA109 for 2021 to 22. If more tax is payable, there will be an interest charge from 31 January 2023. Please note there is no right of appeal against interest charges.  
There is also the possibility of late payment penalties, however, you will have the right to appeal them if they arise.
Thank you.

If I work back my tax return for 2021 to 22 and 2022 to 23 but I have registered for self assessment and tax return for 2023-24 earlier this year with UTR received, do I need to register the self assessment and tax return for 2021 to 22 and 2022 to 23? If not, I encounter a credential error when submitting my 2021 to 22 tax return though third party software (SelfTax), I have ensured my gateway ID, password and UTR correct many times but it did not come through. May I know what the possible cause is? Thank you.

Hi,
If you have not registered to file a return for 2021 to 2022 or 2022 to 2023, our system may not accept these returns if you are using thrid party software.
Please contact our Self Assessment team to update your record to file these returns.
Self Assessment: general enquiries
Thank you.