I owe student loan on 2022/2023 tax year but have paid it all off in 2023/24

I have completed my self assessment - and it says I owe roughly ~£400 from the 2022/23 tax year. But this all appears to come from underpaid student loan (and actually I appear to have paid slightly too much income tax). However, I completed paying off my student loan in 2023/24 tax year. The balance I need to pay has yet to display on my account (I understand that I need to wait 72 hours) - when it does appear should the balance work out that I have already finished paying off my student loan and therefore I am actually owed some income tax back?

Hi Matt Huntt,
You will need to change the answer to no for the student loan as it won't take into account payments from 23/24 on the return.
Thank you. 

Hi - I unfortunately already submitted, what can i do?

Hi,

If you submitted online, you can go back into your account to amend it. If not, you will need to claim in writing.

Thank you.