Cannot create accounts in my organization

Yesterday I created an AWS base account, I'm trying to create accounts in my organization, I'm using the root account for it, but I'm getting the following error:

You have exceeded the allowed number of AWS accounts.

I don't have any other accounts than the Management account, I also checked the limits and it's 10 accounts, am I doing something wrong? could it be that my account is not verified?

Thanks in advance.