What to do if we received a letter saying we owe hundreds more, then a couple days later we got a refund check in the mail for a couple thousand?

[Prayfirst]

We paid our taxes due in March.  Now, it looks like we have a refund and another about due bill.  Not sure what to do?  I'm afraid to deposit the check.

[rjs]

Who is the letter from? Who is the check from? Are they both from the IRS, or is one of them from the state?

[Mike9241]

also what year is the letter for.  sometimes it can take the IRS more than a year to issue a tax bill after a return is filed.