Md. Code, Public Utilities § 17–301

(a) In this subtitle the following words have the meanings indicated.

(b) “Proper invoice” means an invoice that:

(1) contains the contractor’s federal employer’s identification number or Social Security number;

(2) contains the contract or purchase order number or other description of the contract; and

(3) contains or is accompanied by the substantiating information and documentation required by regulation or contract.

(c) “Receipt date” means the date that a proper invoice is received by the Commission.