Idaho Code § 63-3027D: Presumptions and burdens of proof.

(a) A qualified taxpayer and its affiliates shall be presumed to be a part of a unitary business and all income of that business shall be presumed to be apportionable business income if a valid water’s-edge election has been made, except as provided in subsections (c) and (d) of section 63-3027C, Idaho Code.

(b) A taxpayer shall have the burden of proof regarding the issue of whether or not a corporation is a member of a water’s-edge combined group.