If none of the above safe harbor allocation methods fairly reflect the allocation of taxable computer software or computer software services to the state, the seller, service provider, user or consumer may make such allocation based on the best information available to such person if properly supported by the books and records of the seller, service provider, user or consumer. If the commissioner shall challenge or contest the allocation method utilized by a seller, service provider, user or consumer, the commissioner must establish by a preponderance of the evidence 1. that the allocation method utilized by the seller, service provider, user, or consumer was not a reasonable method of allocation, and 2. that the allocation method proposed by the commissioner is the most reasonable of all available or alternative methods.
Miss. Code § 27-65-29