What happens if someone gave false information about taxes?

Don't toy with this sort of thing; you could get into a lot of trouble. Why don't you take a look at the Tax Crimes Handbook , starting around page 102 under the heading "Aiding and Abetting." Note the words "Whoever willfully causes an act to be done which if directly performed by him or another would be an offense against the United States, is punishable as a principal."

While you are acting in a representative capacity under a power of attorney, you are not immune to prosecution if you knowingly perform a criminal act, even if the benefit goes to another party. If the principal (the person who granted the power of attorney) to you (the agent) has obtained a refund based on a false tax return, if you know or should have known that the return was false, if you cash the check, you may very well be held liable for not only the amount refunded but you may also have some criminal liability. On the other hand if you do not know that the return was false but have an uneasy feeling, you may want to check with a qualified person to see if the refund is legitimate.

Being a participant, in some way, to a fraudulent tax return is dangerous. You can get caught up in the web of deceit, especially if IRS Criminal Investigation Division gets involved.