another - how much SA pension question

[coetzeeh]

Please help answer the riddle for a friend.

PAYE and expecting to have a shortfall in tax deducted for the current year of circa £7k (2022/23).

£40k pension allowance used this year but may have some headroom in prior years.
After utilizing annual allowance in current year expecting taxable income to be ~£125k.

So thinking of making a one off payment into pension fund to off set the expected £7k tax bill.
Is the thinking correct?
Assume prior years tax rate at 40%.
What amount of one off payment would be required?

Much appreciated.

[Rufus Stone]

£20,000 assuming payment via relief at source.

But how has the shortfall in tax arisen under PAYE?

[coetzeeh]

Rufus Stone said:

£20,000 assuming payment via relief at source.

But how has the shortfall in tax arisen under PAYE?

One off incremental equity tranche maturing at the end of tax year meant breaching higher tax thresholds.