Progress invoicing is a billing method where a contractor or service provider sends invoices at set intervals during a project, with each invoice covering the percentage of work completed since the last billing cycle rather than waiting for one lump-sum payment at the end. The approach keeps cash moving to the party doing the work and gives the party paying a built-in checkpoint to verify quality before releasing more money. Construction contracts, large government projects, and multi-phase professional services engagements all run on some version of it.
How It Differs From Milestone Billing
These two terms get swapped around, but they are not the same thing. Progress billing tracks the overall percentage of work finished at a regular interval, usually monthly. If a project is 35% done at month end, that invoice covers 35% of the contract value minus what was billed before. Milestone billing ties each payment to a specific deliverable: foundation poured, roof framed, system tested. No deliverable, no payment, no matter how much effort has gone in.
Progress billing fits projects with continuous, steady work where drawing hard lines between phases would be artificial. Milestone billing fits projects with clean, discrete stages. Many contracts blend both, using progress billing inside each milestone phase.
The Schedule of Values Comes First
Before any invoice goes out, the contractor submits a schedule of values. This document breaks the total contract price into individual line items, each representing a specific scope of work or material category. A commercial renovation might carry separate lines for demolition, framing, electrical rough-in, plumbing, drywall, and painting. Each item has its own dollar value, and the sum of all items equals the total contract amount.
The owner or architect reviews and approves the schedule before the first invoice. That approval matters because the schedule becomes the backbone of every invoice for the rest of the project. If line-item values are inflated at the front end and deflated at the back end, the contractor collects a disproportionate share of the money early. This practice, called front-loading, creates a real problem: if the contractor walks off or gets terminated, the owner has paid more than the work is worth and may not have enough contract money left to hire a replacement. Aggressive front-loading can also cross into overbilling, which carries fraud liability. Reviewers scrutinize schedules of values specifically to catch it.
The G702 and G703 Forms
The construction industry has standardized progress invoicing around two forms published by the American Institute of Architects. The AIA G702, formally the Application and Certificate for Payment, is the summary sheet. It shows the original contract sum, approved change orders, total work completed and materials stored to date, retainage withheld, previous payments, and the current amount due.
The G703 Continuation Sheet is the line-by-line backup. Every item from the schedule of values appears here with columns for its budgeted amount, work completed in prior periods, work completed this period, materials stored, total completed and stored to date, and the remaining balance. Completing it means comparing the actual state of each line item against its budgeted value. If electrical rough-in was budgeted at $80,000 and the electrician is halfway done, the G703 shows $40,000 completed for that line. Totals roll up to the G702 summary.
Getting these percentages right matters. Understating completion means the contractor finances more of the project than necessary. Overstating it means billing for work not yet performed, which erodes the owner’s leverage and, on government contracts, can constitute a false claim.
Billing for Stored Materials
Most contracts let a contractor bill for materials purchased and stored on-site even before installation. Custom-fabricated steel sitting in the staging area represents real money already spent. Some contracts also permit billing for materials stored off-site, such as equipment being fabricated at a manufacturer’s facility. Federal contracts require the contractor to prove it holds title to off-site materials and that those materials are allocated to the specific project.1Acquisition.GOV. FAR 52.232-5 Payments Under Fixed-Price Construction Contracts Private contracts typically require insurance certificates, photographs, and warehouse receipts as backup.
Submission, Review, and Payment
Once the paperwork is complete, the contractor submits the invoice to the architect or project manager for review. Many firms route documents digitally through construction management platforms, but paper submissions still happen on smaller jobs. The reviewer compares what the invoice claims against what the job site shows. If the invoice says framing is 90% complete and the reviewer walked the site and saw otherwise, the invoice goes back for revision.
After certification, the invoice moves to the owner’s accounting department. How quickly payment arrives depends on the contract. Federal contracts fall under the Prompt Payment Act, which generally requires payment within 30 days of receipt of a proper invoice.2Office of the Law Revision Counsel. 31 USC Chapter 39 Prompt Payment – Section 3903 Regulations If the agency pays late, it owes interest at a rate set by the Treasury Department, currently 4.125% for the first half of 2026.3U.S. Department of the Treasury. Interest Rates – Prompt Payment Private contracts typically allow 14 to 42 days depending on state law, and most states impose their own late-payment interest penalties.
Retainage: What the Owner Holds Back
Retainage is the portion of each progress payment the owner withholds as a financial safety net. If the approved invoice is $100,000 and retainage is set at 5%, the contractor receives $95,000 and the remaining $5,000 stays in the owner’s hands. It accumulates over the life of the project, creating a pool the contractor earns back only after the work is complete. The purpose is to give the contractor a financial incentive to finish and correct deficiencies.
Private-project retainage usually runs between 5% and 10%. On federal construction contracts, retainage cannot exceed 10% of the approved payment amount, and contracting officers are directed to reduce retainage as the project approaches completion if performance has been satisfactory.4Acquisition.GOV. FAR 32.103 Progress Payments Under Construction Contracts
Retainage release is typically triggered by substantial completion, the point at which the project is finished enough for the owner to use it for its intended purpose even if punch-list items remain. The architect issues a Certificate of Substantial Completion documenting the milestone, and the contract usually requires the owner to release all or most retained funds within a specified number of days. Clean, consistent G702 and G703 records throughout the job make this release smoother. Disputed or inconsistent records make it drag.
Lien Waivers Travel With Each Payment
Owners almost always require a lien waiver alongside each progress payment. The contractor waives the right to file a mechanic’s lien against the property for the amount being paid, which protects the owner from paying twice for the same work.
The critical distinction is between conditional and unconditional waivers. A conditional waiver on a progress payment only takes effect once the payment actually clears the bank. If the check bounces or the wire never arrives, lien rights remain intact. An unconditional waiver takes effect the moment it is signed, whether or not the money has arrived. Signing an unconditional waiver before the payment clears is one of the most common and costly mistakes in construction billing. If the payment fails afterward, lien rights are gone for nothing. The practical rule: never sign an unconditional waiver until the funds are confirmed in your account.
Change Orders and the Timing Gap
Projects rarely finish with the exact scope they started with. When the owner adds work, deletes scope, or the team hits unforeseen conditions, a change order modifies the contract. Each approved change order adjusts the contract sum on the G702 and usually adds or modifies line items on the G703. The G702 includes a dedicated field for the net change from all approved change orders, so a reviewer can see exactly how the contract has shifted from its original value.
The friction comes from timing. Work on a change often begins before the paperwork is formally approved, especially when the condition cannot wait, such as contaminated soil discovered during excavation. The contractor performs the work, but the change order is still in negotiation. The next invoice arrives and the contractor wants to bill for that work. The owner or architect may reject those line items until the change order is signed. The gap between actual costs incurred and billable amounts is one of the most common sources of cash-flow trouble and payment disputes. Keeping a detailed log of pending change orders and their status is essential for managing it.
Federal Contract Requirements
Federal construction contracts add layers of documentation and certification. Under FAR 52.232-5, each payment request must include an itemized breakdown of amounts requested, a listing of work performed by each subcontractor, total subcontract values, and amounts previously paid to each subcontractor.1Acquisition.GOV. FAR 52.232-5 Payments Under Fixed-Price Construction Contracts The contractor must also sign a certification stating that all amounts requested are for performance under the contract terms, that subcontractors have been paid from previous progress payments, and that no amounts are being improperly withheld from subcontractors.
The certification is not a formality. Knowingly submitting a false statement on a government payment application is a federal crime under 18 U.S.C. 1001, carrying up to five years in prison.5Office of the Law Revision Counsel. 18 USC 1001 – Statements or Entries Generally On private contracts, overstating completion percentages to pull cash forward can expose a contractor to state fraud statutes or civil liability. The line between optimistic estimating and fraudulent billing is thinner than most contractors realize, and the consequences land hardest on whoever signed the payment application.
Tax Treatment of Progress Payments
How progress payments get reported for tax purposes depends on the type of contract and the size of the contractor. The default federal rule for long-term contracts is the percentage-of-completion method, which requires the contractor to recognize income proportional to the work done each year. If a two-year contract is 40% complete at year-end based on costs incurred versus estimated total costs, the contractor reports 40% of the expected profit that year.6Office of the Law Revision Counsel. 26 USC 460 – Special Rules for Long-Term Contracts
Small contractors have an alternative. If average annual gross receipts over the prior three tax years do not exceed $32 million (the inflation-adjusted threshold for tax years beginning in 2026), and the contract is estimated to finish within two years, the completed-contract method is available instead.7Internal Revenue Service. Revenue Procedure 2025-32 That approach defers all income and expenses until the project is finished. The cash-flow advantage can be real, especially for contractors who complete multiple short-duration projects each year.
For contractors using the percentage-of-completion method, the IRS applies a look-back rule when the contract closes. If actual income differs from what was reported based on estimates during the project, the contractor either owes interest on underpaid taxes or receives interest on overpaid taxes.6Office of the Law Revision Counsel. 26 USC 460 – Special Rules for Long-Term Contracts The accuracy of cost estimates throughout the project has direct tax consequences beyond the invoicing itself. Contractors who habitually underestimate costs end up paying look-back interest when actual profits come in lower than projected.
Mistakes That Cost Real Money
After all the documentation and review steps, the problems that actually sink contractors are usually simple ones.
- Signing unconditional lien waivers before the payment clears. If the check bounces, there is no recourse against the property.
- Front-loading the schedule of values. Pulling cash forward feels smart until the owner catches it, or until the back half of the job is underfunded and you cannot finish without eating costs.
- Billing for unapproved change orders. The work is real, but the invoice gets rejected because the change order is unsigned, and the subcontractors have already been paid for it.
- Sloppy percentage estimates. Overstating completion damages bonding capacity and credibility with reviewers. Understating it means financing the owner’s project with your own cash.
- Ignoring tax method requirements. Reporting income on a cash basis when the IRS requires percentage-of-completion triggers look-back interest and potential penalties at contract close-out.
The contractors who handle progress invoicing well are the ones who keep the schedule of values honest from the start, document every change order in writing before the work begins, and never sign a waiver until the money is in the bank.