Tax relief on private pension contributions using inheritance royalties from previous tax years

My wife has been out of employment for a 5+ of years and has not been earning. However, in the 2021/22 tax year, she started recieving royalties as an inhertiance (her grandmother wrote books and when she died, she allocated some of the royalties from these books to my wife). These royalties have continued to give her income in the 2022/23 and 2023/24 tax years. The income from these royalties (and any other income) never exceed her personal allowance so she did not pay any tax on the income from these royalties. My wife would now like to pay all of the income earned from these royalties into a Self Invested Personal Pension (SIPP). This would be paid into her pension in the 2023/24 tax year and the total amount paid into her pension would be less than the tax free annual allowance of £60,000 for this tax year. As far as I can tell, these inherted royalties count as income (i.e. if the amount recieved was above her personal allowance, tax would need to be paid) so I believe my wife can claim tax relief for contributions up the the value of these earnings, even though she paid no tax on them. However, I'm unsure if the earnings were in previous tax years, whether she can pay in a single sum in the current tax year and still get tax relief on the whole amount. I would appreciate some help in answering this question. I've been struggling to find any relevant guidance.

Hi,

Tax relief on pension contributions is only due in the year the payment is made and relates to the earnings received for that particular year. You can see guidance here:

Tax on your private pension contributions

Thank you.