You do not report his/her income on your return*. If it has to be reported, at all, it goes on his own return. If your dependent child is under age 19 (or under 24 if a full time student), he or she must file a tax return for 2022 if he had any of the following:
- Total income (wages, salaries, taxable scholarship etc.) of more than $12,950 (2022) ($13,850 2023).
- Unearned income (interest, dividends, capital gains, unemployment, taxable portion of 529 distribution) of more than $1150 (2022) ($1250 2023)
- Unearned income over $400 (2022) and gross income of more than $1150 (2022)
- Household employee income (e.g. baby sitting, lawn mowing) over $2300 ($12,950 if under age 18)
- Other self employment income over $400, including money on a form 1099-NEC
Even if he had less, he is allowed to file if he needs to get back income tax withholding. He cannot get back social security or Medicare tax withholding.
In TurboTax, he indicates that somebody else can claim him as a dependent, at the personal information section (although he files his own return, it is not an "independent" return, he is still your dependent).
Other replies have suggested that the ticket sales (But not the prize) be reported as self employment income and pay self employment tax (SET).** If this is only sporadic income, it can probably be reported as "other income". Other income is treated as unearned income.
*If his only income is from interest and dividends, Alaska PFD or capital gains distributions shown on a 1099-DIV, there is a provision for entering it on your return, using form 8814. This does not apply in your case.
** Self employed persons pay their medicare and social security tax as "self employment tax".
