"Under Texas Uniform Transfer to Minors Act" (also called UGMA, for Gifts to Minors, in some states).  It is the child's property but an adult is the custodian.  The income belongs to the child and is correctly reported with the child's SSN.  Some states allow the age at which the custodianship ends to be set past 18 -- in this case, 21, but I think some even allow 25.  And of course, some parents don't tell the kids about it until they are 30 and get an IRS notice asking why they haven't reported the income.