The Most Common Contractor Scams (And How to Spot Them Before You Hire)

Contractor scams cost American homeowners billions of dollars every year. The FTC consistently ranks home improvement fraud among its top-three complaint categories, and losses are climbing. The good news is that most scams follow recognizable patterns — and once you know what to look for, they're easier to avoid than you'd think.

The most common contractor scams target homeowners at moments of trust: right after you've gotten a friendly quote, right after a storm when you're stressed, or right before work begins when the contractor asks for money upfront. Here's what each scam looks like and how to protect yourself.

What does an up-front cash demand tell you about a contractor?

Demanding full payment — or a large cash payment — before work begins is one of the clearest warning signs in home contracting. Legitimate contractors typically require a modest deposit (10–15% is industry standard, never more than 30%), with the balance paid in stages tied to completed work. A contractor who insists on cash only, or wants 50%–100% upfront, is either going to disappear with your money or has no intention of doing quality work.

Cash is particularly dangerous because it leaves no paper trail. If the contractor takes your money and disappears, you have almost no recourse. Pay with a check or credit card whenever possible. A credit card gives you chargeback rights if the contractor doesn't perform — and that protection is worth a lot.

• Red flag: “I only take cash.”
• Red flag: Wants 50% or more before a single nail is driven.
• Red flag: No written contract, just a verbal agreement and a handshake.

What is the low-bid-then-escalate scam and how does it work?

This is one of the most common contractor scams, and it works precisely because the initial quote feels like good news. A contractor wins your business with an unusually low bid — often 30–50% below what other contractors quoted. Once work begins, the problems start: unexpected “discoveries” require additional materials, the scope “has to expand,” and the final bill ends up far exceeding what a legitimate contractor would have charged. At that point, your home is already torn open and you feel stuck.

The defense is getting at least three written quotes for any significant project. If one bid is dramatically lower than the others, ask why in specific terms. Sometimes it reflects genuine efficiency; more often it reflects either corners being cut or a bait-and-switch already in motion. A reputable contractor can explain exactly what their quote includes and exclude.

Why are door-to-door contractors after a storm a red flag?

After any major storm — hurricanes, hail, tornadoes, flooding — a wave of out-of-state contractors descends on affected neighborhoods. They knock on doors, point to damage you may not even have noticed, and offer to start work immediately. State attorneys general and the FTC issue warnings about these “storm chasers” after every major disaster event. Many are unlicensed in your state, collect insurance money, do substandard or incomplete work, and are gone before you discover the problems.

A legitimate local contractor does not need to knock on your door the morning after a storm. They have existing customers, referrals, and a reputation to protect. Anyone who shows up unsolicited and pushes you to sign immediately — especially if they offer to “handle your insurance claim” — should be treated with extreme skepticism.

• Never sign anything at the door. Tell them you'll call if interested.
• Verify their license in your state before they start any work.
• Call your insurance company directly — do not let a contractor manage your claim.

How do contractors use fake or borrowed license numbers to deceive homeowners?

Some contractors will hand you a license number that belongs to someone else, is made up, has expired, or was revoked years ago. They're counting on you not to check. In a 2019 CSLB sting operation in California, roughly one in four contractors approached by undercover inspectors either couldn't produce a valid license or gave incorrect information. License fraud is more common than most homeowners expect.

The fix is straightforward: look up the number yourself. Every state with a licensing requirement maintains an online database. Search by license number and confirm that the name on the license matches the contractor you're dealing with, that the license is current (not expired), and that it covers the type of work being done. CheckLicensed.comautomates this lookup across all 50 states and flags status issues so you don't have to navigate state websites yourself.

What is the subcontractor substitution scam?

You hire a well-reviewed general contractor. They win your trust, you sign the contract. Then, without telling you, they subcontract the actual work to whoever bids lowest — often unlicensed workers or new crews with no track record. The contractor you vetted may never set foot on your property. The workers who show up may have no verifiable credentials at all.

The best protection is to include a clause in your written contract specifying that any subcontractors must be disclosed and licensed, and that you retain the right to approve substitutions. Ask the contractor upfront: “Will you be doing this work personally, or will you be using subcontractors? If subcontractors, can I see their licenses?” A legitimate contractor will answer directly.

What is a mechanic's lien and how can a contractor put one on your home without warning?

A mechanic's lien is a legal claim a contractor or subcontractor can file against your property if they claim they weren't paid for work performed. The dangerous part for homeowners: you can be subject to a lien even if you paid your general contractor in full, if that contractor didn't pay their subcontractors or suppliers. You can end up paying twice for the same work, or have a lien on your home that clouds your title and prevents you from selling or refinancing.

To protect yourself: always get a lien waiver from your general contractor and any major subcontractors when you make payments. Ask your contractor whether subcontractors and suppliers have been paid before releasing final payment. In some states, you can file a “notice of non-responsibility” to limit your exposure. A title company or real estate attorney can advise you on your state's specific rules.

What does demanding full payment before the job is finished signal?

Legitimate contractors structure payment around project milestones. They bill when the foundation is poured, when framing is complete, when rough-in passes inspection — not in one lump sum before anything happens. A contractor who demands full payment before the final walkthrough has no remaining incentive to fix problems, complete punch-list items, or return if something fails. Once you've paid everything, your leverage is gone.

Standard practice is to retain at least 10% of the contract price until the job is fully complete and you have done a final inspection. Never release that final payment until you are satisfied with the work. A reputable contractor understands this and won't push back hard.

Before any money changes hands on your next project, verify the contractor's license at CheckLicensed.com. It takes two minutes and catches the fake license numbers, expired licenses, and revoked credentials that contractors are counting on you not to check.