If you are an off-the-shelf or purchased-finished supplier of goods to the federal government, your contact closeout is reasonably simple. You will make delivery at a firm, fixed price to the agency to which you have contracted and submit an invoice. The government will receive and inspect the delivery and approve your invoice for payment. Assuming there are no ongoing warranties, logistics support or similar contract line items involved, the government will then closeout the contract, as will you.
In dealing with government officials the small business owner must be aware of regulations regarding procurement