Paying tax but should not be.

Hello. could someone put me right. I have just done a tax computation relating to all my income as projected for the coming year. I am retired and will receive regular pension payments income. However, I have received a letter from one former employer NHS that states that my future pension income from them will be taxed. The amount is relatively small. However, I find this confusing as my forecast tax computation worked out for the coming year 2023-24 shows that i have unused personal allowance. A pension provider making a small reduction on one of my pensions therefore is surely incorrect. They have stated that any tax code error would be the responsibility of HMRC. How do I go about telling HMRC that i am being taxed when i should not be. My tax code is also wrong. I have looked on my HMRC account but it only relates to previous tax years. I would like to send HMRC an email explaining this but finding it difficult. Can anyone put me right as to how to inform HMRC that their tax code is wrong and re-examine this again. I studied accountancy in the past and I have done tax computations. I am sure this is an error. Thank you for your help.

Hi,

If you contact our Income Tax team we can review this and ensure the tax code is correct. If you decide to write to us include an estimate of your earnings from each source so that we can ensure the tax codes are correct.

Income Tax: general enquiries

Thank you.