What must occur for the 30-day payment window to begin regarding invoice processing?

The 30-day payment window for invoice processing begins when a proper invoice is received. This is crucial because the invoicing process is a formal mechanism through which the supplier requests payment for goods or services rendered. For the timeline for payment to initiate, it is essential that the invoice adheres to the required format and contains all necessary details, such as the supplier's information, a description of the goods or services provided, payment terms, and any applicable contract references.

Once a proper invoice is received, it can trigger the internal processes for approval, verification, and subsequent payment by the contracting agency. Without a valid invoice, the payment timeframe cannot start, as there would be no official record to process for payment. The emphasis on receiving the correct invoice ensures that all parties are aligned on the terms of the transaction before funds are disbursed.