When the money arrives
When a contract includes the commercial clause FAR 52.212-4, payment is made for items the Government has accepted that were delivered to the destinations the contract sets out 1.
FAR 32.904 counts invoice payment due dates from two events: the 30th day after the designated billing office receives a proper invoice 2, and the 30th day after Government acceptance of supplies delivered or services performed 3. Under the standard Prompt Payment clause, the due date is the later of the two 4.
FAR 52.212-4 lists what an invoice must include 5, among them the contract number, line item number and, if applicable, the order number 6.
Forecast the gap
Worked example. Contractor E starts a services contract worth $40,000 a month on 1 March and pays its staff every two weeks. It invoices at the end of March and the billing office receives a proper invoice on 2 April, but the government accepts March's services on 5 April. The due date is the later of 2 May (30 days after the invoice) and 5 May (30 days after acceptance), so E plans for payment on 5 May. By then E has paid roughly two months of payroll from its own cash.
Line up financing before you need it
The general standards for a responsible prospective contractor include adequate financial resources to perform the contract, or the ability to obtain them 7.
Under FAR 52.212-4, a contractor may assign its rights to receive payment due under the contract to a bank, trust company or other financing institution 8.
Financing can also come from the Government: performance-based payments are the preferred Government financing method when the contracting officer finds them practical and the contractor agrees to their use 9.
If you are a small subcontractor, FAR 52.219-8 states that it is the policy of the United States that its prime contractors establish procedures to ensure the timely payment of amounts due under their subcontracts with small business concerns 10.
Bids2Bank's BankBridge says plainly that no lender is signed yet, so no funding date is promised 11.
Indented paragraphs are invented worked examples. Tool links open Bids2Bank and need a free account.