How do contractors collect unpaid construction invoices?
How contractors collect unpaid construction invoices — from reminder call to mechanics lien
Short answer
Contractors have one powerful tool most businesses lack: the mechanics lien. File a preliminary notice within the required window (typically 20 days from first furnishing labor or materials) to preserve your lien rights on every job above a threshold. When an invoice goes past due, the sequence is: phone call within 3 days, written demand at 14 days, notice of intent to lien at 30 days, lien filing by the deadline (typically 60–90 days after last day of work). The lien clouds the property title and forces resolution before any sale or refinancing. Most payment disputes in construction resolve at the notice-of-intent stage — the lien threat motivates payment faster than any collection letter.
The mechanics lien is the defining tool of construction collection. Available to contractors, subcontractors, material suppliers, architects, and engineers who contribute to real property improvements, a mechanics lien attaches directly to the property — the GC's slow payment or dispute with the owner does not affect your lien rights as a sub. The lien must be paid off before the property can be sold or refinanced. This leverage does not exist in other industries.
Lien rights require strict procedural compliance. Most states require a preliminary notice — a formal document sent to the property owner, GC, and/or construction lender within a specified window (often 20 days from first furnishing) — to preserve lien rights. If you miss the preliminary notice deadline, you typically lose lien rights entirely regardless of how valid the underlying debt is. Calendar the preliminary notice date on every new job the day you start work.
The notice of intent to lien (NOI) is the step most contractors underuse. Before filing an actual lien, sending a formal NOI gives the property owner and GC a final opportunity to resolve the payment without the cost and process of an actual lien filing. NOIs are often more effective than the lien itself because they arrive before the dispute escalates to court and because property owners have strong incentive to resolve liens before they appear in title searches. Many construction payment disputes settle at the NOI stage.
Retainage is a separate lever. If you have withheld retainage from subcontractors pending project completion, and the GC has withheld retainage from you, the retainage release process creates a natural pressure point: document substantial completion clearly, submit a formal retainage release request in writing, and reference the contract's retainage release provisions. Disputes about retainage are often negotiated separately from progress payment disputes.
For invoices under the small claims threshold ($5,000–$25,000 depending on state), construction small claims is often faster than pursuing a lien through the court system. File in the county where the job was located. Bring photos, signed contracts, lien waivers you have issued, and the invoice documentation. Construction disputes in small claims are factual — the party with better documentation almost always prevails.