Idaho Code § 67-2011: Services — Vouchers for.

Vouchers submitted for services other than the payment of salaries, fixed by law must set forth the particular service rendered, the rate of pay, and the total amount due. Where the voucher covers separate noncontinuous services each item must be separately stated. Such vouchers must contain a certificate from the head of the department or institution to the effect that the services were necessary in the public service, that they were actually rendered as charged, and that the account is correct and just.