Reclaim PPI tax from previous years thru online self-assessment

Nickgdw

I need to reclaim the tax on interest from my PPI claims which were paid out in june 2020. R40 doesn't seem to apply to self employment, so I asked HMRC for help and (eventually) got a response saying to use 'box 17 - Other taxable income – before expenses and tax taken off'. But there is no box 17 on the online form and the closest box to that title is on a page headed 'In 2021-2022 did you...'
TIA

Dazed_and_C0nfused

You need to to make an amendment to your 2020:21 Self Assessment return.

No idea what HMRC are on about to be honest though.

PPI refunds aren't taxable and do not have tax deducted from them.

The statutory interest paid alongside the PPI refund is taxable and does have tax deducted.  

So you need to include the gross interest in the taxed interest section along with the tax deducted.

Then your 2020:21 tax position will be recalculated to take into account the additional income (and tax deducted).

You only have until 31 January 2023 to do this.