Tax refund; claim; contents; form

(1) A claim for a refund shall be in writing and filed with the Tax Commissioner within three years of the date (a) on which the overpayment was made or (b) on which the tax was required to be paid, whichever is later.

(2) The claim shall state the reason for the overpayment and the amount of refund or credit requested.

(3) The Tax Commissioner may prescribe the necessary forms for the filing of a claim for refund.

(4) An amended return reducing the amount of the liability and containing an explanation of the reduction shall constitute a refund claim.