But that was probably wrong advise. If they qualify as your dependent they have to say they CAN be claimed as a dependent even if you don't actually claim them. If they were under 19 on December 31, 2020 they qualify as dependents no matter how much income they made. They don't get a choice. And if they have any unearned income like investments that gets taxed at the parents rate. If you say no you are not a dependent, It might be tax fraud.
When you have to answer yes you are a dependent
https://ttlc.intuit.com/community/dependents/help/when-do-i-have-to-answer-yes-to-being-claimed-as-a...
