Indiana Code Title 10. Public Safety § 10-16-10-9

Sec. 9. (a) A bill or an account may not be made by an officer or enlisted person with a view of the bill or account being paid by the state unless the expenditure is expressly authorized by the laws of Indiana or the adjutant general.

(b) An account may not be paid unless it is accompanied by vouchers or receipts showing by whomever paid or are to be paid, to whom paid, date of service, authority for, and amount of the expenditure, and for what purpose the expenditure was made.