Self Assessment Tax Code

Hi All, Currently doing my first self assessment tax return, I have completed all details and provided all the relevant information to calculate. This is based mostly around the high income charge for child benefit this year, which Ironically I dont fall into next year now. With all the relevant details entered into the system it gives me a calculation of tax owed however the full calculation output shows my personal tax allowance incorrectly. its currently showing the normal 1257 (£12,570) however since around 2016 we have had the marriage tax allowance transfered into my account (recipient) from my wife as donor (as she is not currently working) this should allow for an extra 10% personal tax allowance in my account. according to the portal and payslips for 2023-2024 tax year my code was 1370m - which should allow for roughly £13,700 tax free allowance. The difference on the calculation is circa around £1,130 between that amount and the correct. Wondered if anyone else had any experience of this, within the HMRC portal it does show I receive the allowance and tax code is correct, same on the portal on my Wife's side also showing that tax is transferred. Is there a way to get this corrected on the self assessment calculation (seems the field is not something that is editable). I have checked and the address on my wife's tax account was our old address from a few years ago which I have now aligned correctly, however not sure if now that I have entered the details and its calculated already that this will no longer adjust. I have not yet submitted the self assessment so grateful for any input, have a feeling that if I submit its probably going to sort itself out but would be good to get some clarification if anyone has had this situation before before I submit and overpay by £1,130 and then need to chase to get that amount back as its quite a considerable amount of money. Thanks.

Name removed admin .

Cookies on Community Forums