How do I collect an unpaid invoice as a general contractor?
How to collect an unpaid general contractor invoice
Published May 13, 2026
Short answer
General contractors have two collection advantages most service businesses do not: progress billing tied to milestones (so a stalled invoice can pause future work), and mechanic's lien rights on the property when statutory notice has been preserved. The right sequence is to bill on schedule against the agreed milestones, call on day 3 past due, and preserve lien rights at every step. If a balance ages past 30 days, file the lien before the statutory window closes, then keep negotiating.
General contracting AR is structurally different from other service work because the contract is usually large, the work happens in phases, and you have specific statutory protections most other businesses lack. Progress billing means you bill 20-30% at signing, 20-30% at framing, 20-30% at rough-in, and the balance at completion. Each milestone is its own invoice with its own collection lifecycle.
The mechanic's lien is the most powerful tool you have. Almost every state lets a contractor, subcontractor, or material supplier file a lien on the improved property to secure unpaid work, but the rules are strict and the windows are short. You typically have to send a preliminary notice within 20-60 days of starting work to preserve lien rights, and you have to actually file the lien within 60-120 days of last furnishing materials or labor. Miss those windows and the lien rights disappear.
On the day-3 call for a past-due milestone invoice, lead with the construction schedule, not the money. 'I am calling about the framing draw on the Mitchell project, $42,000. We are scheduled to start rough plumbing Monday but we need the draw cleared before we mobilize.' This frames the conversation as a project-progress issue, not a collection issue, and gives the owner a concrete cost (delay) for non-payment.
For commercial GC work or change orders, get the change order signed before doing the work. Verbal approvals at the jobsite turn into 'I never agreed to that' three weeks later when the invoice arrives. A photo of a signed change order on the foreman's tablet is worth thousands in avoided disputes.
Syntharra handles the day-3 first-party call for general contractors on QuickBooks, Xero, or FreshBooks. The AI confirms the invoice and milestone, reads the balance, and offers to take payment over the phone or via link. Lien deadlines and dispute escalations route back to your project manager for human handling.