Contractor vs Subcontractor: The Real Difference

A contractor signs the prime contract directly with the client and owns the project. A subcontractor signs with the contractor, not the client. The contractor vs subcontractor distinction is not about skill or trade - it is whose name is on the contract, who carries the liability when something goes wrong, and where the money flows first. That one difference changes everything about who owns the risk.

The contractor vs subcontractor divide: who signs what#

In any construction project the chain works like this:

Client - Main contractor - Subcontractors

The client signs one contract with the main contractor (also called the general contractor, or GC). The main contractor then signs separate contracts with each subcontractor they bring in - electricians, plumbers, groundworkers, tilers. The client has no direct contract with any of those subcontractors. They never signed anything with the sparky. They hired you.

This matters because of the legal doctrine of privity of contract: you can only enforce a contract against someone who is party to it. The client's legal relationship is with the main contractor. Full stop. If the plumber floods the bathroom, the client calls the main contractor. The main contractor calls the plumber.

I went through this shift myself when I moved from doing the work to running the jobs. The moment my name was the one on the contract with the homeowner, everything changed. Every complaint, every defect call, every "this is not what I asked for" came to me. I dealt with it, then dealt with the sub. That accountability is the line between the two roles.

Who carries it when things go wrong#

The main contractor carries the primary liability to the client for every piece of work on the project - including work done by their subcontractors. In the US, federal regulations place overall responsibility squarely with the prime contractor. UK construction law takes the same position. You hired the sub. You vouched for them. If they do poor work, it is your problem to fix before it becomes the client's.

Subcontractors carry liability too - but to the main contractor, not to the client. A subcontractor who does defective work can be pursued by the GC for remediation costs or damages. Most well-drafted subcontract agreements include indemnification clauses that require the sub to hold the GC harmless for claims arising from the sub's own work.

This is why the quality of your trade bench is your reputation. If you are running the construction arbitrage model - winning the work and subbing out the execution - a client who is delighted does not care that you were not on the tools. A client who is unhappy does not care who caused it. The contract runs through you.

Where the money flows - and who waits longest#

Money flows down the chain: client pays the main contractor, main contractor pays the subcontractors. The problem is timing. Main contractors are typically paid on milestones or at completion. Subcontractors often wait net 30, 45, or 60 days after invoicing - sometimes longer.

Late payment is chronic in construction. In the UK, the average delay beyond agreed terms ran to over 38 days in recent years, with construction consistently ranked as one of the worst-affected sectors. Subcontractors feel this most acutely because they carry material and labour costs in the meantime.

The main contractor earns the spread - the difference between what the client pays and what the subs charge. On residential renovation work in the US, gross margins of 20-35% on top of sub costs are typical for small jobs. That margin is not free money. It covers overhead, insurance, risk, and the coordination work the GC performs. See how much general contractors mark up subcontractors for a full breakdown of where that spread lands once costs are stacked against it.

How this maps onto construction arbitrage#

If you want to understand what construction arbitrage is, the contractor vs subcontractor distinction is the foundation. Construction arbitrage is the business model where you operate as the main contractor - your name on the client contract - and subcontract the physical execution. You earn the spread. You carry the accountability. You run it as a system instead of being on the tools.

The subcontractor position is different. A subcontractor earns their rate for the scope they execute. They do not manage the client relationship, they do not carry the full project liability, and their income is capped by the hours they or their team can physically work. The construction arbitrage vs subcontracting breakdown goes deeper on how those two positions differ in practice and which one builds a scalable business.

The thing I tell anyone new to this model: you are not hiding behind the sub or passing the work off. You are the named contractor. The client chose you. That accountability is real - and it is exactly what justifies the margin.

Two questions that follow naturally from this one:

Do you have to tell the client you are subcontracting the work? In most cases, no - unless the contract requires it. What you are always obligated to deliver is the result the client paid for.

Can a general contractor subcontract all the work? On private jobs, yes. There is no law requiring you to self-perform any minimum share. You hold the contract; you choose how to execute it.

The full breakdown of how to structure the sub agreements, the client contract, and the margin stack is in THE FAMILY SECRET - How Construction Arbitrage Really Works (coming soon).