Progress Billing: How to Structure Your Billing by Milestone

What Is Progress Billing?

Progress billing is the practice of billing a client based on the percentage of work completed on a project. It's the most common billing method in construction, used on the majority of commercial, industrial, and institutional projects.

Unlike fixed-price billing — where the client is billed the full contract amount regardless of progress — progress billing ties payments to actual performance. The client pays as the work is performed, and the contractor gets paid based on progress.

The Three Common Progress Billing Methods

• Percentage of completion: Billing based on the actual percentage of work completed, measured by cost incurred, labor hours, or physical progress.
• Milestone billing: Billing based on predetermined milestones — e.g., "20% at foundation pour, 40% at framing completion, 30% at finishing, 10% at final acceptance."
• Unit billing: Billing based on completed units — e.g., per square foot, per linear foot, or per installed item.

How to Structure Your Progress Billing

• Define your billing cycle: Most projects bill monthly, but some bill bi-weekly or weekly. The billing cycle should align with your cash flow needs.
• Set clear milestones: If you're using milestone billing, define each milestone in the contract — including what constitutes completion of each milestone.
• Include retainage: Most progress billing includes a retainage percentage — typically 5% to 10% — that is held back until project completion.
• Submit supporting documentation: Clients expect detailed backup — progress reports, photos, lien waivers, and certified payroll reports.
• Follow up promptly: Send invoices as soon as the billing period ends. Delays in invoicing create delays in payment.

How Progress Billing Connects to Your WIP Schedule

Your progress billing should be aligned with your WIP Schedule. The amount you bill each month should reflect the progress reported in the WIP — costs incurred, percent complete, and earned revenue.

When progress billing is out of sync with the WIP, you create over-billing or under-billing positions that don't reflect reality. That distorts your job profitability and can affect your bonding capacity.

Common Progress Billing Mistakes

• Mistake #1 — Billing too aggressively: Billing ahead of progress creates over-billing and strains client relationships.
• Mistake #2 — Billing too conservatively: Under-billing drains cash flow and creates unnecessary financial strain.
• Mistake #3 — Missing deadlines: If your billing cycle doesn't align with your costs, you'll experience cash flow gaps.
• Mistake #4 — Not tracking change orders: Change orders need to be included in progress billing — or they'll never be billed.

Progress Billing and Bonding Capacity

When a surety reviews your bonding capacity, they look at your billing practices. Consistent progress billing — aligned with your WIP Schedule — signals financial discipline. Inconsistent billing practices suggest weak internal controls.

Frequently Asked Questions

Can I bill more than the contract value?

No — not without change orders. Progress billing is based on the contract value plus approved change orders. Billing above the contract value without a change order is over-billing.

What is the typical progress billing cycle?

Monthly is the most common. Some contracts specify bi-weekly or weekly billing for shorter projects.

How do I handle progress billing on a design-build project?

Design-build projects often use milestone billing tied to design completion, permitting, and construction phases. The billing structure should be defined in the contract.

What happens if the client disputes my progress billing?

Most contracts have a dispute resolution process. Documentation — photos, progress reports, and WIP Schedule — is your best defense.