mom did her taxes she got her federal taxes but passed away now we got a check in the mail from the state tax can we cash it

The short answer is, no you cannot cash the check. It's not made out to you. Send it back to the Franchise Tax Board and request it be made out to either (1) the estate (if there's going to be a probate) or (b) to you if there's not going to be. If the check is made out to you, you're signing under penalty of perjury that you're going to share it with anyone who is entitled to part of it. From the Franchise Tax Board website: The administrator or executor of the deceased taxpayer's estate by attaching certified copies of the letters of administration or letters of testamentary to the return, or Entitled to the refund as the deceased taxpayer's surviving spouse or sole beneficiary under the California Probate Code. Attach to the return a copy of Federal Form 1310, Statement of Person Claiming Refund Due a Deceased Taxpayer, or a copy of the death certificate.