In this subtitle the following words have the meanings indicated. “Payment date” means the date of the Commission’s check. “Proper invoice” means an invoice that: contains: the contractor’s federal employer identification number or Social Security number; and the contract or purchase order number or other description of the contract; and contains or is accompanied by substantiating information and documentation as required by regulation or contract. “Receipt date” means the date that a proper invoice is received by the Commission.

It is the policy of the Commission that payment under an authorized, written procurement contract shall be made by the Commission to the contractor within 30 days after the receipt date of a proper invoice.

An amount due and payable under an authorized, written procurement contract and in accordance with law that remains unpaid for more than 45 days after the receipt date shall accrue interest: for the period that begins 31 days after the receipt date; and at the rate specified in § 11–107(a) of the Courts Article.

The Commission is not liable for the payment of interest under this subtitle: if a proper invoice for accrued interest is not submitted within 30 days after the payment date of the amount on which the interest accrued; for more than 1 year and 31 days after the receipt date; on amounts representing unpaid interest; or if the Commission determines there is a dispute regarding any material factor in the contract or purchase order.