Interest on savings PAYE and self assessment

Hi I’m employed and have PAYE tax and I am also self employed and complete a self assessment tax return. I understand I have a personal savings allowance of £1000. If I was to exceed the psa of £1000 in interest and need to pay tax would it be done via my self assessment tax return rather than altering my tax code for my PAYE job? I’m not keen on my tax code changing and the possibility of under and over payments. If I submit my self assessment and pay any tax on interest that way will it stop the change of my PAYE tax code? At what point in the year do you change tax codes? I’m imagining the banks inform HMRC about interest at the end of the tax year so how soon after this do you change tax codes?

Hi Lightbulbmoment G,
When you submit the tax return the tax due on your savings income will be collected through your Self Assessment tax return.
Once your tax return is filed your tax code would then be reviewed.
If you do not want the savings collected in the tax code going forward you need to answer 'NO' to the question on the online tax return.
If you are likely to owe tax for the current tax year (ends 5 April 2025) on income other than employed earnings/pensions e.g. savings or the High Income Child Benefit Charge, do you want us to use your 6 April 2024 to 5 April 2025 PAYE tax code to collect that tax during the year?
Thank you. 

Thank you for answering. Not sure yet if might go over the psa or not for the current tax year so will leave it as is for now. Is it a case of just making sure I have enough to pay any tax incurred when I submit at the end of this tax year? Would rather do that and pay any actual amount than mess my tax code up with estimates - not sure if estimates that’s the right word.

Hi Lightbulbmoment G,
Yes that will be correct if the untaxed savings are not included in your tax code.
Thank you.