Contractor Red Flags to Watch For Before You Sign

Updated September 2026 · Home Project Resources

The contractor red flags that matter most are simple to spot: no verifiable license or insurance, a knock on your door after a storm, a demand for a large payment up front, cash only or a check made out to a person instead of a business, a one-page contract with no scope, and pressure to sign today. Any single one of those is a reason to slow down. Two together is a reason to walk.

Everything on that list is checkable in about fifteen minutes, using your state licensing board, a phone call to an insurance agent, and a tape measure. The homeowners who get burned almost never missed a subtle signal. They saw an obvious one and did not verify it because the person seemed nice and the timing was urgent.

Updated September 2026

A wrong quantity in a bid is a red flag you can catch yourself. Use our free Square Footage Calculator to measure the actual areas being quoted, so a bid listing 900 square feet for a room you measured at 1,100 gets caught before you sign, not on day three.

Contractor red flags before you sign anything

These are the warning signs that show up during the bidding stage, ranked roughly by how reliably they predict trouble.

The single most predictive one is the door knock. Legitimate local contractors are usually booked out and do not need to canvass. Storm chasing crews follow hail and wind, work fast, and are three states away before the first leak shows up. If someone approaches you unsolicited, take the card, verify everything, and get two local bids before you talk to them again.

Verify in fifteen minutes: exactly what to check

You do not need to be an expert. You need to check four things at their source rather than accepting a document handed to you.

1. The license, on the board's own website. Search by the license number and by the business name. Confirm all four of these:

• The status reads active, not expired, suspended or revoked.
• The classification covers the trade you are hiring for. A general license does not automatically cover electrical, plumbing, HVAC or roofing in many states.
• The name on the license matches the business name on the bid, not a similar one.
• The complaint or disciplinary history, which most boards publish.

2. Insurance, from the insurance agent. Ask the contractor for the agent's contact information, then request the certificate of insurance be sent to you directly with your name and project address on it. Confirm general liability and workers compensation separately. A forwarded PDF is easy to alter and easy to have expired last month.

3. The business itself. Look up the business entity registration with your Secretary of State, confirm how long it has operated, and check that the physical address is a real place. A business that changes names every two years is often outrunning its own review history.

4. References you actually call. Ask for three recent jobs of similar type and size, and ask each one four questions: did the schedule hold, how were change orders handled, how was the cleanup, and would you hire them again. Then look at the pattern in online reviews rather than any single review, and read the middling reviews, which are usually the honest ones.

The FTC's guidance on home improvement scams covers the consumer protection side, including cancellation rights on contracts signed in your home, which in many situations gives you a three day window to back out in writing.

The scams that keep working, and how each one starts

The storm chase. A crew appears after hail or high wind, offers a free inspection, and climbs on the roof. Sometimes they find real damage. Sometimes they create it. Then comes an insurance claim they offer to handle for you, a contract signed on a clipboard, and a deposit. Get your own inspection first using the roof inspection checklist, and let your insurer's adjuster do the assessing.

The deposit and disappear. A large up front payment for materials, a promised start date, then delays, then nothing. This is why deposits are limited by law in many states, either as a percentage of the contract or as a fixed cap, and why every payment after the deposit should be tied to a completed milestone.

The lowball and the change order. The bid is written light on purpose: fewer footings, thinner material, no disposal, allowances set unrealistically low. Once demo starts and you are committed, the change orders begin. The defense is a written scope you hand to every bidder and a quantity check you do yourself.

The material swap. The bid says one product, the truck delivers another. Put brand, product line, thickness, grade and model numbers in the contract, and inspect deliveries against that list before installation.

The unpermitted job. Work gets done fast and cheap because nobody pulled a permit. It surfaces at resale, at the next insurance claim, or when a buyer's inspector finds an unpermitted panel. Unpermitted electrical and structural work is the version that can also hurt someone.

The lien trap. You pay the general contractor in full. The general does not pay the lumberyard or the plumbing sub. That supplier files a mechanics lien on your house, and you can end up paying twice. Signed lien waivers with each payment are the defense, and a contractor who cannot explain them is telling you something.

The insurance claim inflation. A contractor offers to cover your deductible or to inflate the claim. That is insurance fraud, and the homeowner who signs the paperwork is a participant, not a bystander.

The moving target crew. Different people show up every day, nobody is in charge, and the person you signed with stops answering. Ask during bidding who will be on site daily and who your single point of contact is.

Red flags after work starts

Trouble usually announces itself in the first week.

• No permit posted when the job required one.
• Work started before the permit was issued, which puts the inspection outcome at risk.
• The crew is different people every day, with no lead on site.
• A request for the next payment before the current milestone is complete.
• A sudden material substitution described verbally as an upgrade.
• Verbal change orders with a promise to write it up later.
• Unsafe practices: no fall protection on a roof, no dust barriers, exposed wiring left live overnight, extension cords running through standing water.
• The site is a mess every evening, which tracks with quality in almost every case.
• Structural elements cut without a plan, which is the single most expensive mistake in remodeling. Anyone opening a wall should be able to explain what they checked, and how to tell if a wall is load-bearing covers what that answer should sound like.
• Inspections skipped or rescheduled repeatedly, especially rough electrical and rough plumbing before drywall goes up.
• Photos discouraged. You should be documenting everything behind the walls before it is covered.

One firm rule for the whole job: never pay ahead of completed work. The final payment is your only real leverage on the punch list, and a job with nothing held back can drift for months.

Worked example: catching a bad takeoff yourself

The fastest way to expose a thin bid is to check its quantities. You do not need to price anything.

A drywall bid on a 14 by 20 foot room

Ceilings are 9 feet. The bid lists 24 sheets and no waste allowance.

• Wall perimeter: (14 + 20) x 2 = 68 linear feet
• Wall area: 68 x 9 = 612 square feet
• Ceiling area: 14 x 20 = 280 square feet
• Total surface: 612 + 280 = 892 square feet
• Sheets, at 32 sq ft per 4 by 8 sheet: 892 divided by 32 = 27.9, so 28 sheets with zero waste
• With a 10 percent waste allowance: about 31 sheets
• Screws: roughly 32 to 36 per sheet on 16 inch framing, so 1,000 to 1,100 screws, which the breakdown in drywall screws per sheet explains

A bid listing 24 sheets is short by about seven, which is either a measuring error or a plan to use 12 foot sheets and count differently. Either way, you now have a specific question instead of a bad feeling, and how the contractor answers it tells you more than the answer itself.

A schedule that does not add up

A painting bid covers 3,200 square feet of wall and ceiling surface, two coats, and promises two painters finishing in two days.

• Coverage required: 3,200 x 2 coats = 6,400 square feet of applied paint
• Labor hours offered: 2 painters x 8 hours x 2 days = 32 hours
• Implied rate: 6,400 divided by 32 = 200 square feet per hour, per painter, including all prep

Rolling open wall at that rate is realistic. Rolling plus masking, cutting in, patching, moving furniture and cleanup at that rate is not. The schedule is the tell, and the same arithmetic runs in reverse on any trade with an obvious unit. The way painters build these numbers is broken down in how to quote a painting job.

Do this check on every trade with a countable unit: flooring by square foot, drywall by sheet, roofing by square, fencing by linear foot and post count, concrete by cubic yard, deck by square foot and footing count. Every calculator on this site exists so you can run a five minute takeoff before a signature.

Contract terms that protect you

A contract is where red flags become enforceable protections. Nine items belong in every one.

On lien waivers specifically. There are four common types: conditional and unconditional, each in progress and final versions. A conditional waiver takes effect when the payment clears, which is the safer one to accept mid job. Ask for waivers from major subs and suppliers too, not just the general contractor, on any project large enough to involve them.

On deposits. Many states cap what a contractor can collect before work begins, either as a percentage of the contract or as an absolute limit, and some require the deposit to be held in a separate account. Look up your state's rule and treat a request above it as a hard stop.

For the full method of lining up bids so they can actually be compared, work through how to compare contractor bids before you start calling anyone.

Green flags: what a good contractor does

Knowing what right looks like makes wrong obvious.

• Shows up to the walkthrough on time and measures instead of estimating from the doorway.
• Asks questions you had not thought about, like where the water shutoff is or how the crew reaches the back yard.
• Names the hardest part of your project without being asked. Someone who says nothing is tricky has not looked closely.
• Gives you a written scope with exclusions listed, because clear exclusions are honesty, not weakness.
• Volunteers the license number and the insurance agent's contact before you ask.
• Explains the permit path and says they will pull it.
• Sets realistic lead times on cabinets, windows and specialty materials instead of promising everything is in stock.
• Puts change orders in writing for a small item early, which tells you how the big ones will go.
• Answers the phone during bidding, which is the best available predictor of communication during the job.

A note on the lowest bid. It is sometimes the right choice, and there is nothing wrong with picking it once the scopes truly match, the quantities check out, and the credentials are verified. What you never want is to choose a bid because it is lowest without knowing why it is lowest.

If you are already in it

Damage control has an order.

1. Stop further payments immediately. Do not pay for work not completed, and do not let a partial job pull more money out on a promise.
2. Put everything in writing. Send a dated letter or email describing the problem, the contract terms it violates, and what you want done, with a deadline. Keep a copy.
3. Document everything. Photos with dates, the contract, all change orders, texts, receipts, and a written timeline of events.
4. Check the permit status with your building department. If the work was unpermitted, ask what is required to bring it into compliance.
5. File with the state licensing board. Many states run a recovery or guaranty fund for homeowners harmed by a licensed contractor, and a filed complaint is often required to access it.
6. File with your state attorney general and the FTC, especially if the contract was signed at your home or there was misrepresentation.
7. Ask your insurer whether any part of the loss is covered, particularly if there was property damage.
8. Consult an attorney about small claims or civil action, and ask specifically about lien deadlines in your state, which are short and unforgiving.
9. Get an independent assessment of what was actually built before hiring anyone to finish it, so the next contractor bids on reality.

Do not let a bad contractor finish the job to save the relationship. Work performed poorly usually has to be removed before it can be corrected, and every additional day of the same crew adds to the removal. Living through the pause is unpleasant, and the survival tactics in how to live through a renovation help, but it beats paying twice.

FAQ

What is the biggest contractor red flag?

An unverifiable license combined with a request for a large payment up front. Those two together account for a large share of the complaints licensing boards receive. Both are checkable in minutes, one on the state board's website and one against your state's deposit limit, so there is no reason to accept either on trust or on a photo of a card.

Should I ever hire an unlicensed contractor?

Not for anything that requires a license in your state, which nearly always includes electrical, plumbing, HVAC, structural and roofing work. Unlicensed work usually cannot be permitted or inspected, is difficult to insure, and often has to be redone before a home sale. For genuinely unlicensed trades such as painting or basic carpentry, verify insurance instead, and get everything in writing.

How much deposit is normal for a contractor?

Enough to cover materials and scheduling, and no more. Many states cap it by percentage of the contract or by a fixed limit, and a few require the money to sit in a separate account, so look up your state's rule and use it as the ceiling. Everything after the deposit should be tied to a completed, verifiable milestone rather than a date.

Is a contractor knocking on my door always a scam?

Not always, but the odds are poor, and they get worse right after a storm. Legitimate local contractors are usually busy with referral work. If someone approaches you unsolicited, do not sign anything at the door, verify the license and insurance yourself, and get two local bids before continuing the conversation.

What is a lien waiver and why do I need one?

It is a signed document in which a contractor, subcontractor or supplier gives up the right to place a mechanics lien on your property for work already paid for. Without one, a supplier your contractor never paid can lien your home even though you paid in full. Collect a waiver with each payment and an unconditional final waiver at the end.

Can I fire a contractor in the middle of a job?

Usually yes, but how you do it matters. Read the termination clause in your contract, give written notice with your reasons, pay only for work genuinely completed, and take dated photos of the exact state of the job that day. Talk to an attorney first when significant money is involved or when a lien has already been filed.

Do I need a permit if my contractor says I do not?

Call your building department and ask them, not the contractor. Permit requirements are local, and a contractor who wants to skip one is usually protecting a schedule or a license status rather than your interests. Unpermitted structural, electrical and plumbing work is the version that resurfaces at resale, and it is the version that can be dangerous.

How do I check a contractor's insurance?

Ask for the insurance agent's name and phone number, then contact the agent yourself and request the certificate of insurance with your name and project address listed on it. Confirm general liability and workers compensation separately, and check the expiration date. If a crew member is hurt on your property and there is no workers compensation coverage, your homeowners policy can end up involved.

Related: Check any bid's quantities with the Square Footage Calculator before you sign. For the full comparison method, read how to compare contractor bids, and for how trades build their numbers, how to quote a painting job. For scope planning, see home remodel cost and home improvement ROI. For what you can safely keep in house, DIY home improvement, and for surviving the job, how to live through a renovation.