D.C. Code § 31-4439
No domestic company shall make any disbursement of $ 100 or more unless the same be evidenced by a voucher signed by or on behalf of the person, firm, or corporation receiving the money and describing the consideration for the payment; and if the expenditure be in connection with any matter pending before any legislative or public body or before any department or officer of any state or government, the voucher shall describe the nature of the matter and the interest of the company therein, or, if such voucher cannot be obtained, the expenditure shall be evidenced by affidavit describing its character and object and stating the reasons for not obtaining such voucher.
D.C. Code § 31-4439
Hospital and medical services corporations, applicability of this section, see § 31-3503. .