How to delete Yahoo account permanently ?

Navigate to the Yahoo email account termination page and log in with your username and password.
Scroll down (and even read!) the fine print about deleting your account, then click the “Continue delete my account” button.
Next, you should see a confirmation screen from Yahoo that gives you one last chance to change your mind. At this stage, you must input your email address again and click on “Yes, terminate this account”.
Your account is now officially deleted—but there is a grace period when you could reactivate it.