Invoicing through IPP and WAWF without rejections

On most federal contracts you do not email an invoice. You submit it through an electronic invoicing system named in your contract, the system routes it to the people who have to accept the work and approve the payment, and the payment office pays from what the system shows. Two systems handle most of this work: the Invoice Processing Platform, IPP, used by many civilian agencies, and Wide Area Workflow, WAWF, used by the Department of Defense.

The cash-flow point is simple. Under the Prompt Payment Act, the government's clock generally runs from receipt of a proper invoice, and a proper invoice is one the system accepts and the government can act on. A rejected invoice has not been received in any sense that matters to your bank account. Every rejection restarts the wait.

IPP: the civilian system

IPP is run by the Treasury Department's Bureau of the Fiscal Service and is free for contractors. Your agency customer enrolls you, you receive an invitation to set up access, and from then on invoices are created inside the system against the purchase orders or contracts the agency has loaded.

How it generally works:

• Invoices are built against the agency's order. You select the award, and the system presents the line items the agency loaded. Your invoice has to match those lines: item numbers, descriptions, quantities, units and prices as the agency recorded them, not as they appear in your own accounting system.
• The agency approves inside the system. Once submitted, the invoice goes to the agency approver. You can see its status, and the system notifies you of approval or rejection with a reason.
• Rejections come back with a code or comment. Common reasons: an award number that does not match, billing against the wrong line item, quantity or amount above what remains on the line, a period of performance that does not match the deliverable, missing required attachments, or an invoice number the system already has.

Agencies differ in what they require attached, how they name line items and how quickly their approvers act. Treat each agency's practices as part of the contract and learn them on the first invoice.

WAWF: the Defense system

WAWF sits inside the Procurement Integrated Enterprise Environment, PIEE, and is required for most Department of Defense contracts. Registration in PIEE requires an active SAM registration and your CAGE code, and you will set up roles for the people who will submit documents.

WAWF is more structured than a simple invoice portal because it combines invoicing with the government's acceptance of the goods or services. The key pieces:

• The contract tells you what to submit. DoD contracts carry a clause with WAWF payment instructions that specifies the document type to use, the routing codes for each office involved, and who to notify. Read it before the first invoice. Submitting the wrong document type is a leading cause of rejection.
• Document types. The common ones are an invoice and receiving report combined, used for most supplies; a two-in-one document for services, where the invoice and acceptance travel together; a stand-alone invoice; and a cost voucher for cost-reimbursement contracts, which routes through the audit agency. Your contract names the one to use.
• Routing codes. Each document carries codes identifying the issuing office, the administering office, the inspector and acceptor, and the payment office. These come from the contract. A single wrong code sends the document to someone who has never heard of your contract, and it sits there.
• Acceptance. A government acceptor has to accept the document before the payment office acts on it. For most documents the payment clock does not start until acceptance, so an acceptor who is slow or who was never notified is a cash-flow problem that looks like a government delay but is often fixable on your side.
• Line items and amounts. Contract line item numbers, quantities, unit prices and totals on the document must match the contract and any modifications. Billing against a line that has been exhausted or not yet funded is rejected.

Why invoices get rejected

Across both systems, the same handful of mistakes account for most rejections:

1. Mismatch with the contract. Wrong award or contract number, wrong line item, wrong unit of measure, price or quantity that does not match the current modification.
2. Wrong document type or routing. The contract specified one thing and the invoice did something else.
3. Billing ahead of the contract. Invoicing before the period of performance ends, before delivery, before an option is exercised, or against unfunded amounts.
4. Missing attachments. Timesheets, progress reports, receiving documentation, certified payroll, or whatever the contract requires to accompany the invoice.
5. Arithmetic and duplicate numbers. Totals that do not foot, invoice numbers reused from an earlier submission, or an invoice that overlaps a period already billed.
6. Stale registrations. An inactive SAM record or a PIEE account whose roles have expired, which stops the submission before anyone reads it.

A pre-submission routine

Build a one-page checklist per contract and have the person submitting run it every time:

• Contract number, modification number and line items confirmed against the latest executed modification.
• Document type and routing codes copied from the contract's payment instructions, not from last month's invoice if a modification has changed them.
• Quantities, units and prices match the contract line, and the remaining funded amount on that line covers this invoice.
• Period of performance or delivery date is complete and matches the deliverable.
• Every required attachment is present and legible.
• Invoice number is unique and the total foots.
• The government acceptor and contracting officer's representative know the invoice is coming and have what they need to accept it.

Then track it. Log the submission date, the acceptance date and the payment date for every invoice. The gap between the first and the second is your rejection-and-acceptance problem; the gap between the second and the third is the government's clock. Knowing which one is costing you weeks tells you where to fix it.

When an invoice is rejected

Read the reason, fix only what it says, and resubmit immediately. Call the acceptor or contracting officer's representative if the reason is unclear; a five-minute conversation beats a second rejection a week later. Keep a note of the cause. After a few months the notes will show a pattern, and the pattern is usually one line on the checklist that needs to be clearer.

The Float is general information, not legal or financial advice. System requirements and agency practices change; follow the invoicing instructions in your contract and the official guidance for the system named in it.