The question comes up every time someone discovers the model. They see the margin. They see the remote operation. They see no tools, no truck, no yard - and the first thing they ask is: is this actually legal?
The answer is yes. Not "yes, but..." or "yes, if you are careful". Just yes. Construction arbitrage is legal because it is general contracting - main contracting, as it is called in the UK - a model that has run the entire construction industry for over a century. Here is the full picture: why it is legitimate everywhere, how the rules differ by country, and where operators actually get into trouble.
Is construction arbitrage legal?
Yes. Construction arbitrage is completely legal. The confusion comes from the word "arbitrage" - it sounds financial, exotic, like it might be skirting a rule somewhere. It is not. Strip away the label and you have general contracting: you find the client, scope the job, hire qualified trades to deliver it, manage the project, and keep the margin between what you sold it for and what it cost to deliver.
That is exactly what construction arbitrage is. And every large contractor on earth operates this way - from Turner and Bechtel in the US to Balfour Beatty and Vinci in the UK. They win contracts, subcontract the delivery, and keep the spread. Solo operators using ads, AI tools, and a subcontractor network are running the same model at a smaller scale. Same legality. Same accountability. Same legitimacy.
What makes it a real business, not a trick
Here is what people confuse: the lightness of the model does not mean it lacks substance. You are not pretending to be a contractor. You ARE the contractor. You are the party the client signs with. You carry the risk. You guarantee the outcome. You are responsible if something goes wrong.
That responsibility - and your willingness to carry it - is what the margin pays for. A client cannot manage fifteen trades, sequence a build, source materials, and coordinate inspections. You can. That service has real value, and charging for it is not a trick. It is a business. The margin is the price of the accountability you carry.
The margin is not a secret. It is what you charge for carrying the risk, managing the project, and guaranteeing the result. Every general contractor in history has been paid for exactly that.
@mointhemarket
Legal everywhere - but the rules differ by country
The model is legal in every major English-speaking market. What changes is the paperwork: whether you need a licence, how you register and pay tax, and which insurance is mandatory. The table below is a current snapshot for the five biggest markets. Treat it as a starting point - the exact rule depends on your country and, in the USA and Australia, your state, so always confirm the current requirement for your specific location before you start.
| Country | What the model is called | Licensing | Tax & registration | Key compliance point |
|---|---|---|---|---|
| USA | General contractor (GC) / prime contractor | State-by-state. ~33 states require a GC licence; some set it by project value (e.g. California needs one on jobs over $1,000). A few states (CO, CT, IL, KS) have no statewide GC licence. | Form an LLC and get an EIN from the IRS. Contractors usually pay sales/use tax on materials, not on the service. | General liability insurance, workers' comp once you have employees, and a surety/contractor bond in many states (California: $25,000). |
| UK | Main contractor / principal contractor | No general builder's licence. But the trades you hire must be certified where required - Gas Safe for gas, Part P for notifiable electrical work. | Register a company at Companies House and register with HMRC under the CIS (Construction Industry Scheme). VAT once turnover passes the threshold. | Make CIS deductions from subcontractors, get building control sign-off for structural work, and carry public liability insurance. |
| Canada | General contractor | No national licence; it varies by province/municipality. BC licenses residential builders; Alberta needs a prepaid contractor's licence if you take deposits; Ontario has no statewide GC licence. | Get a CRA Business Number and register for GST/HST once revenue passes $30,000 (rate varies: 5% AB, 13% ON, etc.). | Register for WCB/WSIB workers' compensation, and use trades certified under provincial rules (electrical, gas). |
| Australia | Builder / building contractor | Mandatory state licence: QBCC in Queensland, VBA in Victoria, NSW Fair Trading (required for residential work over $5,000). Companies need an ABN. | Get an ABN and register for GST once turnover reaches $75,000 (10% GST). | Home warranty / domestic building insurance is mandatory above state thresholds (NSW over $20,000, VIC over $10,000, QLD over $3,300), plus public liability. |
| New Zealand | Builder (Licensed Building Practitioner for restricted work) | General contracting is not licensed, but Restricted Building Work (structure and weathertightness of homes) must be done or supervised by a Licensed Building Practitioner (LBP). | Get an IRD number and register for GST once turnover passes $60,000 in any 12 months. | A written contract is required for residential work over $30,000, plus building consent and an LBP for restricted work. |
Sources, current as of 2026: USA - CSLB and IRS; UK - gov.uk (CIS); Canada - CRA (GST/HST); Australia - QBCC and business.gov.au; New Zealand - building.govt.nz. Rules change - confirm the current figure for your location before you rely on it.
The non-negotiables: how to run it clean
Construction arbitrage stays legal - and stays profitable long-term - when the operator runs it like a real business. The specifics differ by country (see the table), but the principles are identical everywhere:
- Proper contracts. A signed contract with your client before any work starts. Scope, price, payment terms, variation procedure, and what happens if something goes wrong. No contract means no protection - for you or for them.
- Get licensed if your location requires it. Most US states and all Australian states require a general contractor or builder licence; the UK and New Zealand do not licence general contracting itself. Check your own jurisdiction in the table above and register before you take on work that needs it.
- General liability insurance. Public liability in the UK and Australia, general liability in the US and Canada. Non-negotiable. If a tradesperson damages a client's property or a third party is injured, you need cover. Most clients ask to see a certificate before signing.
- Certified trades where the law requires it. Gas and electrical work, and structural calculations, must be done by certified trades almost everywhere (Gas Safe and Part P in the UK, licensed trades in the US and Australia, LBPs for restricted work in NZ). Using unqualified labour where certification is legally required is where operators cross a real line - and it is completely avoidable.
- Permits and building control. Structural work, extensions, changes of use, and certain alterations require a permit or building-control sign-off in every market. Managing that process is part of your role as the contractor. It is not an optional extra.
- Paying subcontractors properly. Pay what was agreed, on time, under a written contract. Using subs and not honouring the deal destroys your network and creates legal exposure. The relationship with your trades is the engine of the model.
- Register your business and handle local contractor tax. Set up the right entity, register for the tax that applies to you - CIS in the UK, sales/use tax in the US, GST/HST in Canada, GST in Australia and New Zealand - and declare your margin as income. Clean books also make the business worth significantly more when you decide to sell.
The concerns people raise - and the reality
Here are the objections that surface online, and what they actually mean:
| The concern | The reality |
|---|---|
| You are not a qualified tradesperson | General contractors are not required to hold trade qualifications. Your role is to manage the project. You must use certified trades for work that legally requires it - and you are responsible for ensuring they hold the right certs. |
| You are hiding your margin from clients | No. You quote a price for a completed job. The client buys an outcome, not an itemised labour sheet. Every contractor in the industry prices this way. There is no law requiring you to disclose your costs. |
| The client does not know you are using subcontractors | Unless your contract explicitly says all work will be done in-house (it should not), subcontracting is assumed and entirely normal. It is how the industry has always worked. |
| You could take the money and disappear | A scammer does that. An operator delivers the job. The model is not the risk - the person running it is responsible for the outcome. Same as any business in any industry. |
| What if a subcontractor does bad work | You stand behind it. Rectification is part of the deal. That is exactly why the margin exists - it covers the risk that you carry. Build in a snagging period and a retention where appropriate. |
What actually gets operators into trouble
The model is not the risk. The execution is. Here is what creates real legal and financial exposure - and every single item is avoidable:
- Taking a deposit and failing to deliver. If you take money for work you never intend to complete, that is fraud in every country. Run the job properly or do not take the deposit.
- Using uncertified trades for work that legally requires a licence. An uncertified gas fitter on a boiler, an unlicensed electrician signing off a panel. Illegal and potentially dangerous everywhere. Always verify certifications before any work starts.
- Working unlicensed where a licence is required. In most US states and all of Australia, contracting above the threshold without a licence is itself illegal - and unrecoverable in court. Get licensed first.
- No written contract. A handshake deal with a client is not a contract. When the scope changes - and it always does - you need written terms to protect both sides.
- Cash-in-hand, off-the-books operation. Undeclared income is tax evasion, not smart business. It also makes the business worthless if you ever want to sell it, and creates serious exposure with the tax authority.
- Ignoring permits and building regulations. Structural work without sign-off creates latent liability that follows the property - and you - for years. It is not worth the shortcut.
Staying legal is simple - and it compounds
Every item on the clean-operations list above doubles as good business practice. Contracts protect you. Insurance protects you. Registering and paying tax properly keeps the authorities off your back. Certified trades mean the work is done right and signed off. Clean books mean the business has a real value when you decide to exit.
The operators who build the biggest, most valuable businesses in this model are also the cleanest operators. Not because they are afraid - because they understand that a business built on proper foundations is an asset. A business built on grey areas is a liability. The players who last choose the asset every time. Stupid money cuts corners. Smart money builds systems.
For a full breakdown of how the model works - the sourcing, the pricing, the systems - read construction arbitrage explained, or see how much money you can make and how to start with no experience. For real operator numbers and the open playbook, go to constructionarbitrage.com. For daily breakdowns of the model in the real world, follow @mointhemarket on Instagram.
Legality is one question; legitimacy is another. For the sceptic's version with real Reddit threads answered, read is construction arbitrage legit - Reddit's verdict.
The operators running clean, profitable construction businesses at scale are inside Contractor Club. Entry is by application. If you think you belong in the room, leave your details and the circle will decide.
Request entry to Contractor Club⟶The bottom line
Construction arbitrage is legal. It is general contracting - main contracting in the UK - the same model used by the largest construction firms in the world, available to solo operators who know how to source clients and run systems. Do it cleanly - contracts, the right licence for your location, insurance, certified trades, proper tax - and there is no legal issue, no grey area, and no catch. The only thing between you and a profitable, legitimate construction business is whether you actually run it like one. That is the whole game - and only players know.
Frequently asked questions
Is construction arbitrage legal?+
Yes, everywhere. Construction arbitrage is simply general contracting (called main contracting in the UK) - a business model that has been the backbone of the construction industry for over a century. Every major contractor subcontracts work and keeps a margin. It is fully legal as long as you operate like a real business: proper contracts, insurance, paying subcontractors, following local regulations, and declaring your income.
Do I need a licence to run a construction arbitrage business?+
It depends entirely on your country and, in the USA and Australia, your state. Some places require a general contractor or builder licence (most US states, all of Australia); others do not licence general contracting at all but require the trades you hire to be certified (the UK). See the country-by-country table below for the USA, UK, Canada, Australia, and New Zealand. The figure to check is always the current rule for your specific location.
Do I need a trade qualification to run a construction arbitrage business?+
No. As the general contractor, your role is to manage the project, not swing the tools. You need to understand scope, manage people, and deliver outcomes - not hold a trade certificate. Qualified, certified trades are used for the work that legally requires certification (gas, electrical, structural, etc.) under your local rules.
What insurance do I need for construction arbitrage?+
At minimum, general liability insurance (called public liability in the UK and Australia). If you employ staff you typically need workers' compensation (employers' liability in the UK). In some markets a surety bond or home warranty insurance is also mandatory - for example a contractor bond in California or domestic building insurance in Australia. Exact requirements depend on your country, state, and the scale of jobs you run.
What is the difference between legal general contracting and a scam?+
A legitimate construction arbitrage operator delivers what they sell: real building work, completed by qualified trades, paid properly, under a signed contract. A scam takes money and disappears, or uses unqualified labour to cut corners. The model itself is legal. The ethics depend entirely on how you run it.
Where can I learn more about running construction arbitrage the right way?+
constructionarbitrage.com is the open resource for the model - real numbers, real systems, and the full playbook. Follow @mointhemarket on Instagram for daily, unfiltered breakdowns of how operators actually run it. The Family Secret book is coming to Amazon - get on the list.
The human behind The Playbook
mointhemarket Managing construction businesses across continents - with full location freedom. Running several at once. Bought and sold many more.
Go deeper
Learn the model, then get in the room
The full breakdown of construction arbitrage lives on our sister site, constructionarbitrage.com. When you want the operators who actually run it, join the Construction Arbitrage Players community.
My book The Family Secret - how construction arbitrage really works - is coming soon.
Only Players Know
The game is real. The room is closed.
Contractor Club is a private, application-only circle of construction arbitrage operators. If you think you belong inside, apply and the circle will decide.
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