High income child benefit charges

Recently had a request from HMRC to file a self assessment to pay this charge which I have done for 2022-2023. However I was not aware of this charge so was wondering how I would pay charges for previous years?

Hi Phil Laird,
Please refer to:
High Income Child Benefit Charge
Thank you. 

Hi Still unsure about how to register for previous years? Could you be more specific? Do I need to phone the helpline? Do I need to send a letter?

Hi P L

To register for previous tax years for Self Assessment you can submt a SA1 form or contact HMRC.
You can submit the SA1 online at Register for Self Assessment if you are not self-employed.
You can contact HMRC at Self Assessment: general enquiries

Thank you