Pension & high income child benefit charge & notifying HMRC

Hello, I am struggling to 1. understand how to calculate adjusted net income and 2. understand how to notify HMRC that my adjusted net income is under the £50,000 threshold. My pension contributions come out of my salary before I pay tax on them. Am I right that this means my net adjusted income is calculated by total income minus these payments? If this is correct, I am under the threshold. How do I notify HMRC that I am under the threshold of £50,000? How would you know that I have done this calculation? I am concerned that if I leave this I will be faced with a bill and a fine. But there is no information on this on your site that I can see. Thanks,

Hi,

You would only be required to notify HMRC of this if we have requested a Self Assessment tax return be completed for the year. If we have, please contact our Self Assessment team who can review if a return is required and cancel the request if appropriate.

Self Assessment: general enquiries

Thank you.