Riptonian71

Thank you, how do you amend a historic tax year return which was completed online?

When completing my Self Assessment for TY22/23 I miscalculated by losses to be carried forward by £300. I even documented the calculation in the notes section in the return which highlights my error in calculation. The error isn't in my favour. The losses available to be carried forward was documented in section 47 of the TY22/23 online form. When completing TY23/24 return in section 45 losses brought forward and used in year do I have to use the exact number I specified in section 47 of the TY22/23 form or can I add the missing £300 and add a note pointing to the documented inaccurate calculations (in the TY22/23 form) in the TY23/24 notes box? Or do I just have to suck up the loss of the £300? Any advice would be much appreciated