Self Assessment - Underpaid tax included in PAYE coding (Page 1 of 2)

I am doing a self assessment and I'm stuck on this section. The question and help note reads: "Amount of underpaid tax for earlier years included in your tax code for 2023-24 (from your PAYE Notice of Coding). If you pay tax under PAYE, your 6 April 2023 to 5 April 2024 tax code may have been adjusted to collect tax you owe for earlier years. Look at your 6 April 2023 to 5 April 2024 PAYE Coding Notice (P2). If it includes an 'amount of underpaid tax for earlier years' then put this amount in the box above." I did have some underpaid tax and my tax-free amount on my 2023/24 tax code notice was adjusted by £679 in order to recover the £185 of tax owed. However, it is not clear which figure I'm supposed to state as my answer. I assume it would be £185 because that is the amount of tax that I'd owed, but I wanted to check to be sure. Is it the adjustment figure or the actual amount of tax owed? Can you please confirm. Thanks

Hi
It would be the underpayment of tax that was collected not the restriction in your code to collect this. From you figures supplied it would be the £185 figure.