You do not need to do anything. He does not need to file since his total income is less than $1050. That income simply goes unreported.
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 2018 if he
had any of the following:
1. Total income (wages,
salaries, taxable scholarship etc.) of more than $12,000 ($6350 in 2017).
2. Unearned income (interest,
dividends, capital gains) of more than $1050.
3. Unearned income over $350 and
gross income of more than $1050
4. Household employee income
(e.g. baby sitting, lawn mowing) over $2100 ($12.000 if under age 18)
5. Other self employment
income over $400, including box
7 of a 1099-MISC
**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. Enter at Less common income / Child's
income.
