Untaxed Interest estimate for 2025/6

How do I change the untaxed interest on savings and investments for the next tax year (April 2025 onwards) ... I can see you have worked out my tax code for next year based on estimating I will earn the same level of untaxed interest on savings and investments as the actual figures for 2024/25. This wont be the case as 2024/25 was a one off and I will earn less than £500 interest.

Hi,
To update your untaxed interest estimate for 2025 to 2026, write to us, or contact our Income Tax team.
Income Tax: general enquiries
Thank you.

This can’t be done by phone, I’ve tried and been told it can’t be updated. You have to wait for the banks to inform hmrc of the actual figures. Seems ridiculous that you can decide in advance that I will owe you tax!