Amending 2021/2022 For Forgetting to include Work Pension Contribution

Hi, I filled out self-assessment for 2021/2022 using commerical software, as I lived in the US for part of it and had split-year tax treatment. After starting to prepare for my self-assessment 2022/2023, I realized I didn't include in my 2021/2022 return the pension contributions I made as part of my PAYE employer pension, and so I think I overpaid tax for last year by a significant amount. From what I understand, do I have to write a letter to HMRC and physically mail it with this information to get the overpaid tax returned/applied to my 2022/2023 taxes? Could I say in my 2022/2023 self-assessment that I overpaid last year? Or is there some other way of fixing the issue?

Hi Jacob,

You will need to amend your 21/22 tax return, either by submitting the amendment online or writing to:

'H M Revenue and Customs BX9 1AS',

You will need to detail the amounts of pension payment entitled to tax relief, along with supporting evidence.

Unfortunately, as this is the first time you are claiming pension relief, we cannot accept an amendment by telphone.

Thank you.