Child Benefit high income self assessment - backdated tax years

Hi all, We recently started receiving Child benefit and our first payment was backdated by 3 months. As the higher earner I know that some of it will need to be paid back through self assessment After calling HMRC, I was able to find out the dates which the first payment covered - 29th Jan '24 - 16th June '24. This of course straddles two tax years Using the tax calculator, I need to pay back £399 which falls into the 2023-24 tax year. No issue with this, it's entirely as expected and matches the figure the person on the phone had given me. I was ready to register for self assessment before October of this year but came across the below which is noted above the calculator results: "If you're making a new claim between 6 April 2024 and 8 July 2024 and are calculating your backdated amount, you do not need to send a separate Self Assessment tax return for 2023-2024. Add the estimated Child benefit and tax to your 2024-2025 Child Benefit tax calculation results" Sorry if this is an obvious question, but does that mean I needn't take any action until Oct 2025? I can register then and when completing the tax return itself for 2024-2025, be sure to add the £399 received (and £399 owed back) along with the rest? I spoke to several HMRC people on the phone about this as I want to ensure I complete it accurately and on time. No one has mentioned this so thought I would ask here Thanks in advance

Hi,
Yes, based on the information on www.gov.uk if a new claim between those dates and first payment received in the 2024/25 tax year then included in the 2024/25 Self Assessment. 
Thank you.