You can cancel your account anytime.
If you are logged in using your password, you will be prompted to re-enter it.
If you are the Account Owner, first make sure you have downloaded your data.
After you cancel your account, you will not be able to log in and all your data will be permanently deleted.
If you are the Account Owner and you cancel your account, the accounts of the users you have created will also be deleted. Both you and these users will be notified by email of your account deletion.
If you are a User created by an Account Owner you can also delete your account. Both you and the Account Owner will be notified by email of your account deletion.