Neb. Rev. Stat. § 77-2106.02

The Tax Commissioner, upon satisfactory proof rendered to him or her of the overpayment of transfer tax in any case, shall issue a certificate of the amount of such overpayment and the party entitled to a refund on account of such overpayment. Such certificate shall constitute prima facie evidence of such overpayment and the person or persons entitled to a refund on account of such payment.