Hi Ka Chun Chow,
In 2022/23 tax return, your foreign income was taxed in the UK and created payments on account, so that you can pay tax for 2023-24 in two instalments during the year.
If you will no longer have any foreign income, you may find that a Self Assessment tax return and payments on account are non longer required.
Please have a look at the Self Assessment criteria tool here:
Check if you need to send a Self Assessment tax return
If a tax return is no longer required, you will need to contact the Self Assessment helpline on 0300 200 3310 or via webchat here:
Self Assessment: general enquiries
Where you will be able to close down your Self Assessment record.