Every telecommunications carrier required to make a return and pay any tax under this chapter shall preserve records of the gross proceeds of sale as the commissioner may require and every carrier shall preserve for a period of three years and three months all invoices and other records of telecommunications services purchased for resale. All of these books, invoices, and other records must be open to examination at any time by the commissioner or any duly authorized agent of the commissioner.
N.D.C.C. § 57-34-04.4