42.15.328 FORM OF CLAIM FOR REFUND
(1) A claim for refund may be in the form of an amended return, a formal claim, or any written instrument signed by the taxpayer, clearly stating the facts concerning payment of the tax and the grounds upon which the claim is based. If the claim is not made on an amended return form, it must be mailed to:
DEPARTMENT OF Revenue
P.O. Box 5805
Helena, MT 59604-5805.