Payment arrears for closed tax year - implications for Child Benefit tax charge

At the end of June 2024, I am due to be paid income arrears from the 2023/2024 tax year. My income in the 2023/2024 tax year was £48,486.56 . As this was below £50,000 I was not liable for the high income child benefit tax charge (my wife claims child benefit for our three children). The income arrears due to be paid in June 2024 relate to a NHS pay uplift to be backdated from April 2023 (6% uplift and £1,250). I just wondered if this income arrears payment will move me above the £50,000 threshold for payment of the high income child benefit tax charge for the tax year 2023/2024, even though the payment of the arrears is due to take place in the 2024/2025 tax year? Am I liable for payment of the high income child benefit tax charge in the tax year 2023/2024 and therefore required to complete self-assessment? Thank you very much for your assistance.

Hi,
The income is taxed on a receipts basis which means it is taxed in the year it is paid.
It would only affect earlier years should you wish to have it allocated to the years that it actually relates to if this is more beneficial to you.
If you were to have it backdated, this cannot be done until after 5/4/25 when your full years income details are held.
Thank you.