how was the a/c titled and did you have your own money in the a/c. best to talk to a lawyer because whether you had an ownership interest in the a/c pre-death is a legal question, not a tax question.
however, if you had an ownership interest in the a/c in past years, each of you was supposed to report their respective share of the activity. the same would be true in 2021 until he died. then if you're the heir, you would report 100%
