HMRC not getting information from banks

I knew this year I owed tax on interest on bank accounts. I am not registered for self-assessment and was under the impression HMRC would contact me letting me know the amount. However, I heard nothing so I contacted HMRC. It turned out they had reviewed my account for the year and did not have interest from my bank accounts. I had to then tell them the figures and today paid the tax owed. Had I not been on top of my finances or dishonest HMRC would have missed out the amount. Please review your procedures, as HMRC should not be missing out on this revenue. My query is the next step. From March 2024, I have taken steps to ensure I no longer get any interest going forward. Therefore, I do not want my tax code amended in April. I am aware the tax code is amended based on interest the previous tax year. However, in my case this is not correct as from March 2024 last year until April this year I will earn zero interest. How can I ensure my tax code is not amended in April?

Hi Lloydsnakelifts,
If your think the bank interest present in your 25/26 tax code is incorrect, contact us by webchat or phone here:
Income Tax: general enquiries
To allow us to update it.
Thank you. 

Or else (if you have a HMRC personal tax account) you can do it here: https://www.tax.service.gov.uk/check-income-tax/income-summary. Click on "add missing investment income", answer the various questions until you get to "Do you have investment income that has ended?". It worked for me.