Can / Should I amend a return?

I've just completed my 2022-23 self assessment, and during the process I spotted an error in the spreadsheet I use. Upon checking, I found the same error was present in the spreadsheet for 2021-22. I've corrected this and found that I have over-declared profit to the tune of around £1800, meaning I've over-paid tax. I believe I can amend the 2021-22 return up until the 31st of January, but can I make amendments which will presumably mean I'm due a tax refund? In addition, is such an amendment likely to result in an investigation, which will likely cost me far more in time than the few hundred in tax I've overpaid? (In other words, is it worth the hassle or am I going to cause myself more problems than it's worth?) Thanks!

Hi,

The deadline for amending the 2021 to 2022 tax return was 31 January 2024.

Thank you.

Yes, sorry, I hadn't realised how slow it was to get replies via this forum. In the end I did decide to submit an amendment, but I now have a question. Originally my profits were just above the threshold to pay Class 4 NICs, but the in the revised return they are below. My revised calculation shows the revised income tax correctly, but is still showing Class 4 and Class 2 NICs as due. I do not pay Class 2 NICs voluntarily as my salaried job pays enough to qualify for credits. When an amended return takes the profits below the Class 4 threshold, are NICs recalculated, or only income tax?

Hi Stephen Hughes,
The class 4 should also be recalculated, it may be worth calling 0300 200 3310 for your records to be checked.
Thank you.