PAYE hmrc Estimated Projected Untaxed Interest Figure

As I have now transferred a bulk of my savings in to an ISA account the figure that hmrc have used in their How you tax-free amount is calculated in the details of a new tax code I have been sent is a considerably higher projected estimate than the real situation. How do I get this corrected as it has an adverse affect on my code. I also do not think that the estimated figure is a realistic one based on the savings interest I received tax last year how do I get hmrc to give me a breakdown of the untaxed interest amounts they consider I have received.

Hi,
We cannot access your personal records on the forum
If you have a personal tax account you can amend your estimated income online to update your tax code here:
Personal tax account: sign in or set up
Alternatively, you can contact HMRC to review/update here:
Income Tax: general enquiries
Thank you

Sorry wrong reply posted previously to this query - my Reply should have read : This doesn't require access to personal records it is a general question that I would have considered would be something others would want an answer to. Let me put the question another way ..is it possible to get a detailed breakdown of how the revenue have calculated the untaxed income figure for a completed tax year and would it be possible to get a detailed breakdown of how the revenue have estimated the untaxed income for the current tax year they are issuing a tax code for. If so how can this be requested? If not why not?

I have never come across any process to request such a breakdown. My completely speculative guess is that such information, if it exists, is in some unstructured form that would require a human employee of HMRC to manually process your request. I suggest it is likely to be easier to forget about figuring out where the existing number came from, and instead prepare your own estimate of the total taxable interest you expect to have received by 5th April, and then submit that to HMRC (in the ways suggested by HMRC Admin). Alternatively, if you will be submitting a Self Assessment anyway this year, you might consider it not worth it to try to correct your code sooner, and just rely on the Self Assessment to refund any overpayment.

Thanks again Max I note that hmrc have chosen to ignore my question with their seemingly instantaneous response to almost everything that they are unable to access personal records which once more shows they haven't really even read what they have been asked yet alone considered it could have general implications of public interest. Thank you though Max

Hi DetaxTherapy,
Untaxed income figures in a tax code would have been provided by yourself or agent at some point previously, usually via your most recent self assessment tax return, or possibly in correspondance with HMRC. The tax code will then keep that figure in your code untill we are advised otherwise by yourself that it is no longer applicable or has changed.
Thank you.