How to Protect Yourself as a Subcontractor From Nonpayment

Nonpayment is the single biggest financial risk subcontractors face in construction. A GC who goes bankrupt, disputes your invoice, or simply refuses to pay can leave you holding unpaid invoices for work you've already performed and materials you've already purchased. The legal tools to protect yourself exist — but only if you use them correctly and on time.

Understand Your Lien Rights Before Work Begins

Your most powerful protection against nonpayment is your right to file a mechanic's lien. A mechanic's lien is a legal claim against the property where you performed work. Once filed it attaches to the title and prevents the property from being sold or refinanced until your claim is resolved. Property owners take lien claims seriously because they directly affect their ability to close transactions.

The critical thing to understand is that your lien rights are not automatic in every state. In many states you must take specific steps to preserve those rights before you can file a lien. Missing those steps means losing your protection entirely.

Serve Your Preliminary Notice on Time

Most states require subcontractors who do not have a direct contract with the property owner to serve a preliminary notice within a specific timeframe after first furnishing labor or materials. In California this is a 20-Day Preliminary Notice. In Florida it is a Notice to Owner within 45 days. In Michigan it is a Notice of Furnishing within 20 days. In Arizona it is a Preliminary 20-Day Notice.

The deadline is strict. A subcontractor who starts work on day one and serves the notice on day 25 has already lost lien rights for the first five days of work. In some states missing the preliminary notice deadline entirely means losing all lien rights for the project regardless of how much you are owed.

Serve your preliminary notice on every project in every state that requires it. Do not wait to see whether payment becomes an issue. By the time payment is a problem it is often too late to serve notice.

Document Every Payment and Every Invoice

Maintain a complete payment record on every project. Keep copies of every invoice, every payment received, every signed contract, every change order, and every written communication about payment. If a dispute arises your documentation is your evidence.

Get change orders in writing before performing additional work. Verbal agreements about scope changes are nearly impossible to enforce. If a GC asks you to do something outside your original contract, stop work until a written change order is signed. This is not being difficult — it is basic business protection.

Know Your Lien Filing Deadline

Your lien filing deadline is your last line of defense. Most states give subcontractors 60 to 120 days from the last day they furnished labor or materials to file a lien. Missing this deadline means permanently losing the right to file regardless of how much you are owed.

Track your last day of work on every project and calculate your lien deadline immediately. Put it on your calendar. Do not assume you have time — construction disputes often drag on longer than expected and it is easy to miss a filing deadline while waiting to see if payment arrives.

Check Whether the Project Has a Payment Bond

On public construction projects — schools, government buildings, infrastructure — mechanic's liens cannot be filed against the property because it is government owned. Instead federal law and most state laws require the prime contractor to carry a payment bond that guarantees payment to subcontractors and suppliers.

If you are working on a public project ask the GC for a copy of the payment bond at the start of the job. Bond claims have their own deadlines — often shorter than lien deadlines — and failing to file a timely bond claim can leave you with no recourse on a public project.

What to Do When Payment Stops

When a payment is late the first step is a direct conversation with the GC. Many payment delays are administrative and resolve quickly with a phone call. Document that conversation in writing with a follow-up email summarizing what was discussed and what was committed.

If direct communication does not resolve the issue send a formal written demand for payment by certified mail. A written demand creates a documented record that the debt is acknowledged and payment was requested.

If the formal demand does not produce payment consult a construction attorney immediately. You have a limited window to preserve your lien rights and a construction attorney can advise you on the specific steps required in your state.

Lien Waivers and Your Rights as a Sub

One area where subcontractors frequently create problems for themselves is signing lien waivers prematurely. Never sign an unconditional lien waiver before confirming that payment has cleared your account. An unconditional waiver releases your lien rights immediately upon signing regardless of whether payment was received. If the check bounces after you sign an unconditional waiver you have permanently given up your legal protection for that payment.

Use conditional waivers throughout the project. A conditional waiver only releases your lien rights once the specified payment is received. If payment fails the conditional waiver fails with it and your rights are preserved.

In all 12 statutory states — Arizona, California, Florida, Georgia, Massachusetts, Michigan, Mississippi, Missouri, Nevada, Texas, Utah, and Wyoming — use only the state-mandated statutory waiver form. A non-compliant form may be unenforceable even if properly signed.

The Bottom Line

Protecting yourself from nonpayment requires action before problems arise. Serve your preliminary notice on time on every project. Document every payment and every invoice. Know your lien filing deadline and track it. Check for payment bonds on public projects. Use conditional lien waivers throughout the project and only convert to unconditional after payment clears.

The subcontractors who get paid are the ones who have their paperwork in order before the dispute starts.

For more on how lien waiver management works across the construction payment chain see our lien waiver management guide.

Frequently Asked Questions

What is the most important step a subcontractor can take to protect against nonpayment?

Serve your preliminary notice on time on every project. In most states failing to serve the required notice within the deadline permanently eliminates your right to file a mechanic's lien regardless of how much you are owed.

Can a subcontractor file a lien after signing a lien waiver?

Only if the waiver was conditional and the condition was never met. A conditional waiver only becomes effective when the specified payment is received. An unconditional waiver is effective immediately upon signing and cannot be undone even if payment never arrives.

How long does a subcontractor have to file a mechanic's lien?

It depends on the state. Most states allow 60 to 120 days from the last day you furnished labor or materials. Missing this deadline means permanently losing the right to file.

What happens if the GC goes bankrupt before paying you?

File your mechanic's lien immediately if you have not already done so. Once the bankruptcy automatic stay goes into effect filing a lien becomes significantly more complicated. A lien filed before the bankruptcy stay is generally treated as a secured claim.

Do you need a lawyer to file a mechanic's lien?

You can file a lien yourself in most states but a construction attorney can ensure the filing is procedurally correct and advise on enforcement. A defective lien filing can be challenged and dismissed, so professional guidance is worth the cost on significant claims.

Waivr is a document generation tool and does not provide legal advice. Always consult a licensed attorney for your specific situation.