1. The Storm Chaser
How it works: After a hailstorm, hurricane, tornado, or major rainfall, unlicensed contractors flood the affected area. They knock on doors, offer free inspections, and "discover" damage that may or may not exist. They collect large insurance deposits and either disappear, do substandard work, or leave mid-project.
Warning signs: Contractor appears at your door unsolicited within days of a storm. They offer to "handle the insurance claim for you" (illegal in most states without a public adjuster license). They want a large deposit before any work begins. Their truck has out-of-state plates or no permanent business address.
What to do: Never sign anything at the door. Call your insurance company directly to file the claim yourself. Hire a local, licensed contractor with a verifiable permanent business address. Verify their license before any conversation about work.
2. The Cash Discount / Skip the Permits
How it works: The contractor offers a significant "discount" — often 10–20% — if you pay cash and let them skip pulling permits. This sounds like a win for both parties. It isn't. The discount is usually less than what it costs to do the work properly. You absorb all the risk: unpermitted work, voided insurance, unsellable property.
Warning signs: Any contractor who proactively suggests skipping permits. "The city takes forever" is not a legitimate excuse. The cash-only discount surfaces after you've already gotten emotionally invested in moving forward.
What to do: Decline immediately. Require that all required permits are pulled in your name before work begins. The contractor's reason to skip permits is that the work won't pass inspection — that is the problem you are inheriting. For more on why permits matter, read our permit guide.
3. The Suspiciously Low Estimate
How it works: A contractor bids 30–50% below every other quote. You hire them. Once work begins, a cascade of "unexpected issues" drives the price back up to — or above — the other bids. By then you're mid-project with a partially demolished kitchen or an open roof.
Warning signs: The bid is dramatically lower than others with no clear explanation. The quote lacks itemization. The contractor can't explain specifically what they're doing differently to achieve the lower price. There is no contingency for unforeseen conditions.
What to do: Ask the low bidder to walk you through every line item and explain exactly where the cost savings come from. If they can't, the bid is not real. A bid that can't withstand a 20-minute explanation doesn't belong in your decision. Read our full guide to red flags in contractor estimates.
4. The Large Upfront Payment / Deposit Grab
How it works: The contractor requires 50% or more upfront — ostensibly to "order materials" or "secure your spot." After payment, contact slows, then stops. The contractor either disappears entirely or moves on to the next deposit and never returns to your project.
Warning signs: Required deposit exceeds 30–40% of total project cost. Payment is requested before a signed contract. The contractor can't provide references from recent, similar-scale projects. They pressure you to pay quickly or claim the price will increase.
What to do: Limit upfront payments to what is genuinely needed for mobilization and initial materials — typically 10–25% for most residential projects. Require a signed contract before any money changes hands. Never pay with cash or wire transfer for large amounts. Our guide to safe payment schedules explains exactly how to structure this.
5. The Fake License
How it works: The contractor shows you a license or recites a number. The license belongs to someone else, is expired, or covers a different trade. Because most homeowners don't actually look it up, it works. The fraudulent contractor completes work that won't pass inspection — or doesn't complete it at all.
Warning signs: Contractor is reluctant to give you their license number in writing. They claim they're "in the process of renewing." The name on the license doesn't match the name on their business card, truck, or invoice. They discourage you from "wasting time" verifying.
What to do: Look up every contractor on your state licensing board's public portal before the first site visit. It takes five minutes. Confirm the license is active, current, and matches the trade and name they're representing. For the full process, see our license verification guide.
6. The Bait and Switch
How it works: The contractor bids with premium materials — a specific shingle brand, a particular tile, a named appliance. You sign the contract. The installed materials are lower grade. The substitution either happens without notice or is buried in a change order you didn't fully read.
Warning signs: Contract language says "or equivalent" without defining equivalence. Materials are installed before you can inspect them. Receipts and delivery manifests are unavailable. The finished product looks different than the samples shown.
What to do: Specify materials by manufacturer, model, grade, and color in the contract — not just a description. Require that the contractor provide delivery receipts showing what was actually ordered. For cabinetry, tile, windows, and roofing especially, inspect materials on-site before installation begins.
7. The Uninsured Subcontractor Trap
How it works: Your contractor has insurance. Their subcontractors do not. A subcontractor is injured on your property, or their uninsured work damages your home. Because the sub isn't on your contractor's policy (or the contractor's policy has exclusions), the liability falls on your homeowner's insurance — or directly on you.
Warning signs: Your contractor can't tell you how many subs they use or who they are. They are vague about whether subs carry their own insurance. The COI they provide only covers the GC, with no mention of subcontractor liability.
What to do: Ask your general contractor to provide certificates of insurance for every subcontractor on your project. For specialty subs — electrical, plumbing, HVAC — verify their trade licenses independently. Our full COI verification guide explains exactly what to look for.
8. The Abandoned Project
How it works: Work begins, partial payment is made, then the contractor becomes unavailable. They cite supply chain issues, other emergencies, or a sick crew member. Days become weeks. You now have a partially demolished bathroom, an open roof, or a half-poured foundation — and no contractor.
Warning signs: Contractor is unresponsive to calls and texts for more than 24 hours without explanation. Work has slowed without an explanation tied to specific conditions. They ask for another advance payment before the last milestone was completed.
What to do: Do not make the next scheduled payment until the current milestone is complete and inspected. Issue formal written notice (email with read receipt) that work must resume by a specific date or you will terminate and engage a replacement. Keep every payment tied to verified, documented completion. See our guide on what to do when contractor work goes wrong.
9. The Predatory Change Order
How it works: The base bid is competitive. Once work begins, a stream of change orders inflates the final cost by 30–100%. Each change order is individually reasonable-sounding: "we found rot under the subfloor," "the original wiring is undersized," "the manufacturer changed the product." Some are legitimate. Many are not.
Warning signs: Every project discovers new problems that require more money. Change orders appear verbally or via text rather than as formal written documents. The contractor resists putting contingency language in the original contract. They calculate change-order pricing on the spot without documentation.
What to do: Your contract must require that all change orders be in writing, signed by you, before any out-of-scope work begins. Include a clause stating that any work performed without your written authorization is at the contractor's expense. For the full framework, read our change order guide.
10. The Lien Trap
How it works: You pay your general contractor in full. Unknown to you, your contractor failed to pay their subcontractors or materials suppliers. Those subs and suppliers can legally file a mechanic's lien on your property — even though you paid the GC. Your title is now clouded, and you may have to pay again to release the lien.
Warning signs: Your contractor is vague about who their suppliers and subs are. They resist providing final lien waivers. Material deliveries are sporadic or you receive calls at the property from suppliers checking on invoice status.
What to do: Before final payment, require a signed, unconditional lien waiver from the general contractor and every named subcontractor and supplier. Do not release the final payment without them. This is standard practice — a professional contractor will not object. Our lien waiver guide explains the process fully.
The Single Best Defense Against All of These
Every scam on this list is significantly harder to execute against a homeowner who (a) verifies credentials upfront, (b) uses a written contract with clear payment milestones, and (c) documents everything. None of that requires legal expertise. It requires thirty minutes of preparation before the project begins.
If you've already encountered a contractor acting in bad faith, submit a Signal to CraftAuthority Alliance. Documented patterns protect the next homeowner.