you must be referring to the kiddie tax
it doesn't matter whether you claim him or not. the 8615 goes with his return.
so you won't get into trouble. he could.
Who Must File
Form 8615 must be filed for anyone who meets all of the following conditions.
1. You had more than $2,200 of unearned income.
2. You are required to file a tax return.
3. You were any of the following:
a. Under age 18 at the end of 2020
b. Age 18 at the end of 2020 and didn’t have earned income that was more than half of your support, or
c. A full-time student at least age 19 and under age 24 at the end of 2020 and didn’t have earned income that was more than half of your support.
4. At least one of your parents was alive at the end of 2020.
5. You don’t file a joint return for 2020.
