Question on whether our son needs to file income tax return for TY2020

Our son is in college and would normally not need to file an income tax return for 2020, since he, as a dependent child on our return, doesn’t have earnings above $12400 and has no other source of income like interest or dividend.

We have a question on whether he needs to file a return in 2020, because we had an unexpected issue with his Roth IRA. He had a paid summer internship in 2020 at his university. He opened a Roth IRA in November 2020. However, we didn’t realize he’d would receive a 1098T instead of a W2 for the summer work. Our search show that PhD students (but he is not) could use that income on a 1098T for Roth IRA contribution. So, we have had to remove the “excess” contribution.

Timeline summary

  • Summer 2020: he had a paid internship at his university

  • Nov 2020: he opened a Roth IRA

  • Feb 2021: he received a 1098T, which means he had no eligible income for a Roth IRA

  • Mar 2021: brokerage processed his “removal of excess” form, which resulted in a) moving $6000 from TY2020 contribution to TY2021, b) a check mailed to him for balance above $6000 from investment gains since account opening in nov 2020.

Since the removal of excess form was processed in March of 2020, we were told by the brokerage phone agent that the 1099-R would not be generated until Jan of 2022. Is this correct? If correct, then it seems that he would not need to file a return for 2020, right?