What about tax refund checks?

A tax refund check is personal property. When you are married and you file a joint return, the tax refund belongs to both of you.  If the tax refund is deposited in a joint account, either one of you can withdraw the money. See What about bank accounts?

If you get the tax refund as a check, it can only be cashed if both of you endorse it (sign the back of the check).