Yahoo will let you create the account, but then you'll have to go through a whole set of other steps to create a COPPA-compliant email account, including having

Yahoo will let you create the account, but then you'll have to go through a whole set of other steps to create a COPPA-compliant email account, including having a parent provide a credit card. That's different from how they would handle it if they had an existing account on Yahoo Mail and found out that the owner was less than 13 - I suspect they would have to turn it off as well, because they won't let you create a non-COPPA account once you've admitted you're under 13.