To have a customer account, you must be at least 13-years-old. If you are under the age of 13, you may not create an account on the Site.
To sell on TurboSquid, you have to be of legal age to sign a binding contract in the country where you reside. This age is 18 in most countries. If you are younger than 18, you can use an adult's account with the permission of the account-holder. However, the account-holder would be responsible for everything done with that account, including royalty payments.