How to spot a building scam before you sign
Most NZ builders are competent and honest. A small minority are actively running scams designed to take homeowner money and disappear. This guide is about that minority — the specific patterns they use, the warning signs that show up before you sign, and the verification steps that almost always catch them. It's the difference between a renovation you'll enjoy and a story you'll tell with regret.
Sign 1 — The door-knock or cold-call
Almost every NZ building scam starts the same way: a builder turns up at your door, or cold-calls, claiming they noticed your roof / driveway / fence / cladding needs urgent work. They happen to be "working in the area" and can give you a great price if you act today.
Reputable builders almost never door-knock — they're busy with referred work and don't need to. The door-knock builders are sourcing customers from desperation, not reputation. The "urgent" framing exists to short-circuit your verification.
Sign 2 — Cash-only or cash discount
A builder who insists on cash, or offers a meaningful discount for cash payment, is almost always either evading tax (IRD will eventually catch them, and your contract evidence disappears) or working under-the-table because they're not legally registered.
Cash also means: no GST receipt, no proof of payment for your records, no recourse via credit card chargeback, and major problems claiming on insurance later. Legitimate builders give written invoices and accept bank transfer.
Sign 3 — Refusal or reluctance to share their NZBN / legal name
Every legitimate NZ building business has a New Zealand Business Number. Asking "what's your NZBN?" should produce an instant answer. Any hesitation, defensiveness, or "why do you need that?" is a flag.
Their NZBN unlocks every other verification step — Companies Office search, director history, gazette filings, court records. A builder who knows their record is bad knows you can find out via this number, and they'll try to keep you from getting it.
- "It's complicated" — flag
- "I'm changing companies right now" — flag
- "I use my mate's company" — major flag
- "Just trust me" — walk away
Sign 4 — Excessive upfront deposit or partial cash advance
Reputable NZ builders take a deposit of 5-10% at contract signing. Scam builders typically ask for much more — 30%, 50%, sometimes 100% upfront — using high-pressure justifications ("materials are about to spike", "my supplier wants cash now", "this is what protects us both").
The actual reason: they need your money to fund their existing debt or pay someone else, and once they have it, they have no real incentive to start your job. The classic scam is a builder with 4-5 concurrent customers, all of whom have paid large deposits, none of whom have actually had work start.
Sign 5 — Trading name with no traceable company behind it
Most NZ builders trade under a brand name ("Premium Build Co") different from the legal entity name ("Premium Build Co Limited" or even "John Smith Holdings Limited"). That's normal.
What's not normal: a trading name that doesn't trace back to any registered company on the NZBN register. A trading name with no legal entity behind it means you have no party to sue if things go wrong, no consumer protections, and no way to file a Disputes Tribunal claim. The builder is operating informally — and almost certainly running multiple jobs the same way.
Sign 6 — Pressure to sign quickly
Legitimate builders are usually 2-6 months booked out. They'll quote you, follow up after a few days, and patiently work with you over weeks to refine the scope. They're playing a long game built on referrals.
Scam builders need money this week. They use artificial urgency: "if you sign today the price is locked", "I have a crew available next week but I'd need to commit them now", "my prices go up Friday". This pressure is designed to prevent you from doing the verification that would expose them.
Sign 7 — No reviewable physical work / no completed jobs to visit
Ask any builder you're considering for the addresses of three completed jobs you can drive past. Reputable builders will give you a list within minutes — they're proud of their work and previous customers are usually willing to vouch.
Scam builders give vague answers: "those jobs are in Wellington, hard to get to", "my customers prefer privacy", "I've just moved to NZ from Australia, my work is over there". The lack of verifiable completed work in NZ is a strong signal you're looking at a serial scammer.
The verification checklist (5 minutes)
If a builder passes initial smell-test, do these checks before signing anything:
- Search the legal entity name on nzbn.govt.nz — confirm status is "Registered" and incorporation date is more than 12 months ago
- Note the directors. Search each director by name on companiesoffice.govt.nz — note any other companies they've been involved in and their status
- If restricted work, search the LBP on lbp.govt.nz — confirm current licence with no disciplinary matters
- Search the legal name + the directors' names on Stuff, NZ Herald and RNZ — any negative coverage is significant
- Drive past at least one completed job and inspect the workmanship
Skip the manual checks.
CheckMyBuilder runs every check covered in this guide automatically — NZBN, LBP, court records, director history, news mentions and an AI risk score. One report, one fee, no afternoon spent on government websites.
Frequently asked questions
- What should I do if I've already paid a deposit and now suspect a scam?
- Stop paying immediately. Send a formal demand letter requesting refund of any unearned portion. Document everything in writing. If the builder is uncooperative, escalate to the Disputes Tribunal (up to $30k, $59 to file). See our guide on recovering a deposit for full process.
- If a builder ticks one or two of these flags, are they definitely a scammer?
- No — some legitimate builders have one or two of these traits (e.g. an honest one-person sole-trader might offer a cash discount, even though we'd advise against accepting it). But if a builder triggers three or more of the seven warning signs, you're looking at a high-risk situation that requires aggressive verification.
- Are scam builders mostly door-to-door operations?
- Many are, but the more sophisticated ones look completely professional — slick website, polished quote, prompt responses to email. The difference shows up in the verification: a sophisticated scammer's company history, when you check the public record, usually shows multiple previous failures. The website hides what the registers reveal.
- Is there a NZ regulator I can report a suspected scam to?
- Multiple, depending on what's happening. For licensed building practitioners doing dodgy work, complain to MBIE at lbp.govt.nz. For tax fraud, IRD. For more serious fraud involving large sums, the Serious Fraud Office at sfo.govt.nz. For consumer protection breaches, the Commerce Commission. For criminal activity, NZ Police.
- Does CheckMyBuilder detect builders running scams?
- We can't detect intent — we can only detect public-record patterns. But the most common patterns scam builders use (previous liquidations, multiple short-lived companies, court rulings, regulator actions) all show up in our reports. A clean CheckMyBuilder report isn't a guarantee, but a flagged one is a clear signal to walk away.
Related guides
This guide is general information for NZ homeowners and is not legal or financial advice. Names of registers, associations and dispute bodies are accurate at time of publication. Always confirm critical details on the official source before acting.