You do not file that income on your tax return, if the account is in his name and SS#. If it has to be reported at all, you grandson will have to file a return of his own.
You do not get a 1099-B for closing a "savings account". The account must have been a brokerage of mutual fund, to generate a 1099-B.I If the capital gain on the sale was less than $1050, it does not need to be reported.
