Payments made in 2020 for academic term beginning in the first quarter of 2021 can be used to claim a tuition credit or deduction on your 2020 tax return.
If he is claimed as a dependent, on your tax return, then you (not the student) are allowed to claim the credit, even though your son actually paid the tuition.
Books and other "required course materials" (supplies and specialty clothing) are also qualified expenses.
