N.D. Cent. Code § 25-01.1-30
An officer designated by the supervising department for each institution under its control shall prepare two monthly statements showing first the payroll and second the expenditures of every kind during the preceding month. Such statement must be signed by the officer, approved by the superintendent of the institution, and filed with the supervising department on a date fixed by the supervising department for the examination and audit of such department. Attached thereto must be the affidavit of the officer stating that the services therein specified were rendered and that the goods and other articles therein specified were purchased and received by the officer or under the officer's direction at the institution and were purchased at a fair cash market price on credit not exceeding thirty days, that neither the officer nor any person in the officer's behalf had any pecuniary or other interest in the purchases made, that the officer did not receive any pecuniary or other benefit therefrom, directly or indirectly, by commission, percentage, deductions or in any other manner whatever, and that the articles contained in such bill conformed in all respects to the invoiced goods received and ordered by the officer or the samples from which the goods were purchased, both in quality and quantity. Such monthly statement must be accompanied by the original invoices of all institutional purchases and a complete itemized statement of each institutional expenditure. If any invoice or statement, or any part thereof, is found objectionable, the supervising department having control of such institution shall endorse its disapproval thereon with its reasons therefor, and shall return it to the management of the institution, and when the matter disapproved of is corrected, the statement and invoice must be returned to the supervising department.
N.D.C.C. § 25-01.1-30