Tax Year Prior to 2020: I co-own a business with my son and I wasn't paid anything and he files those returns separately. what do I do?

[KarenL2]

If you co-own a business with your son, he should file those taxes separately (as you said) as a Partnership or an S-Corporation, if the business has elected to be taxed that way.  He should send you a Schedule K-1 to report on your personal tax return.  He should also receive a Schedule K-1 from the business to report on his tax return.