Paying tax on savings interest

I will be due to pay tax on savings interest next financial year. I'm employed so I understand my tax code will be changed so this can be paid automatically. Will my tax code be changed for the whole year or will this be a one-off payment? Is there an alternative way to pay this? Thanks

Hi,
Once reviewed, if you have underpaid tax then this would normally be collected in the next full tax years code. If you want to pay as a one off payment then you will need to contact our Income Tax team once you receive the tax calculation.
Income Tax: general enquiries
Thank you.