A main contractor is the single construction firm an owner hires to deliver an entire project, acting as the central point of responsibility for the budget, the schedule, the subcontractors, and the finished building. In the United States this role is usually called the general contractor. The owner signs one contract with this company, and the company handles everything else: hiring the trades, ordering materials, running the site, carrying the required insurance, and answering to regulators if something goes wrong.
The appeal of the arrangement is simple. Instead of coordinating twenty specialty firms, the owner deals with one company that absorbs the day-to-day friction of construction and delivers a completed structure at an agreed price.
What the Role Looks Like Day to Day
The main contractor’s job is to turn architectural plans into a physical structure on time and on budget. That means hiring and scheduling subcontractors, ordering materials, securing the site, arranging temporary utilities, and providing heavy equipment like cranes and scaffolding.
On any given day the work is more logistical than physical. Rerouting deliveries because a concrete pour ran long. Pulling an electrician forward in the schedule because framing finished early. Replacing a plumber who walked off the job. When a subcontractor misses a deadline, materials arrive damaged, or weather delays the roof, the main contractor absorbs the disruption and adjusts. The owner’s exposure to that chaos drops dramatically.
Who Is Liable to Whom
Construction projects run on a strict contractual chain. The property owner signs a contract with the main contractor. The main contractor signs separate contracts with each subcontractor. The owner and the subcontractors have no direct contractual relationship with each other, a legal principle known as privity of contract.
What that means in practice: if an electrician’s faulty wiring causes a fire, the owner’s claim runs against the main contractor rather than the electrician, because only the main contractor is in privity with the owner. The main contractor is the single point of accountability, and that comes with real financial risk. If a plumber walks off the job, the main contractor has to find a replacement, cover the added cost, and then pursue its own separate claim against the defaulting subcontractor.
How Money Moves Through the Project
Payment follows the same chain as liability. The owner pays the main contractor at agreed milestones, typically monthly progress payments tied to completed work. The main contractor then pays each subcontractor according to its own subcontract terms.
On federal projects, the government must pay the contractor within 14 days of receiving a proper request for progress payments, and within 30 days for final payment.1Acquisition.GOV. Prompt Payment for Construction Contracts
Most construction contracts also include retainage, a percentage of each payment that the owner holds back until the project is complete. Retainage typically runs between 5% and 10% of each progress payment. The withheld funds give the contractor a financial incentive to finish punch-list items and correct defects rather than move on to the next job. Main contractors usually withhold retainage from their subcontractors at the same rate.
Flow-Down Clauses
Main contractors routinely include flow-down clauses in their subcontracts. These provisions incorporate the terms of the prime contract (the owner-contractor agreement) into every subcontract by reference, so the subcontractor is bound by the same quality standards, scheduling requirements, safety obligations, and dispute procedures the main contractor agreed to with the owner. A subcontractor who never reads the prime contract cannot later claim ignorance of a requirement that flowed down from it.
Conflicts arise when a subcontract’s specific terms contradict the prime contract. Courts generally try to read both documents together, but when that fails, the subcontract’s specific language usually controls. Experienced main contractors include an order-of-precedence clause spelling out which document governs.
Licensing Requirements
Most states require main contractors to hold a license before they can legally bid on or perform construction work. The process typically involves passing an exam covering trade knowledge and business law, proving a minimum number of years of field experience, and posting a surety bond. Many states also require proof of general liability insurance and workers’ compensation coverage as a condition of licensure.
Not every state regulates at the state level. Roughly a dozen states, including New York, Illinois, Ohio, Missouri, and Kansas, leave licensing to cities and counties rather than imposing statewide requirements. That does not mean contractors in those states can operate without any credential; the rules depend on where the project sits. Hiring an unlicensed contractor where a license is required can void the contract entirely in some jurisdictions, leaving the owner with limited legal recourse for defective work.
Bonds the Main Contractor Must Post
A performance bond guarantees that the project will be completed according to the contract terms. If the main contractor defaults, the surety either hires a replacement contractor to finish the work or compensates the owner up to the bond amount. A payment bond serves a different purpose: it guarantees that subcontractors and material suppliers will be paid, even if the main contractor runs into financial trouble.
Federal law requires both bonds on any government construction contract exceeding $100,000.2Office of the Law Revision Counsel. 40 USC 3131 – Bonds of Contractors of Public Buildings or Works Under those rules the performance bond must equal 100% of the original contract price, and the payment bond must be at least that amount as well.3Acquisition.GOV. 52.228-15 Performance and Payment Bonds-Construction Most state and local public projects impose similar bonding requirements, and many private owners require them on large commercial projects too.
Bond premiums typically cost between 1% and 3% of the total contract value for financially healthy contractors, though the rate climbs higher for firms with weaker credit or limited bonding history. The main contractor pays the premium, but the cost is almost always built into the project bid.
Insurance a Main Contractor Needs
Several layers of insurance have to be in place before work starts.
Commercial general liability insurance covers third-party bodily injury and property damage. If a beam falls and damages a neighboring building, or a visitor trips over exposed rebar, this policy responds. It does not cover the contractor’s own employees or the contractor’s own property; those require separate policies.
Workers’ compensation insurance is mandatory in nearly every state and covers medical expenses and lost wages for employees injured on the job. Builder’s risk insurance, sometimes called course-of-construction insurance, protects the structure itself during construction against fire, theft, vandalism, and certain weather events. The owner’s contract typically specifies which party buys the builder’s risk policy.
Owners and upstream parties routinely demand two endorsements on the main contractor’s liability policy: additional insured status, which extends the policy’s protection to the owner, and a waiver of subrogation, which prevents the insurer from suing the owner after paying a claim. Subcontractors are usually required to carry matching endorsements naming the main contractor as additional insured.
Safety Responsibility Under OSHA
OSHA holds the main contractor responsible for jobsite safety in ways that catch many firms off guard. Under the multi-employer citation policy, OSHA can fine a main contractor for hazardous conditions created by a subcontractor, even if no main contractor employee was exposed to the danger.4Occupational Safety and Health Administration. Multi-Employer Citation Policy The theory is that the main contractor, as the controlling employer, has the authority to require subcontractors to fix unsafe conditions and must exercise it.
The standard applied to controlling employers is reasonable care, a somewhat lower bar than the duty an employer owes its own workers, but still demanding. OSHA evaluates reasonable care by looking at how often the main contractor inspects the site, whether it has a system for correcting hazards promptly, and whether it enforces compliance through progressive discipline. A contractor that knows a subcontractor has a poor safety record is expected to inspect that work more frequently.4Occupational Safety and Health Administration. Multi-Employer Citation Policy
Federal regulations also require every employer on a construction site to designate a competent person, someone qualified to spot hazards and authorized to stop work immediately to correct them.5eCFR. 29 CFR 1926.20 – General Safety and Health Provisions OSHA defines a competent person as someone capable of identifying existing and foreseeable hazards and empowered to take prompt corrective action.6eCFR. 29 CFR 1926.32 – Definitions A main contractor should make sure not only that its own competent person is present, but that each subcontractor has one as well.
What the Fines Look Like
OSHA penalties are steep enough to change the economics of a project. As of 2026, a single serious violation carries a maximum fine of $16,550. Willful or repeat violations jump to $165,514 per violation. Failure to correct a cited hazard after the abatement deadline can cost $16,550 per day the violation continues.7Occupational Safety and Health Administration. 2026 Annual Adjustments to OSHA Civil Penalties On a large jobsite with multiple open violations, total exposure can easily reach six figures in a single inspection.
Changes During Construction
No construction project finishes exactly as drawn. Hidden site conditions, owner-requested upgrades, and design errors all generate changes to the original scope. A change order is the legal mechanism for incorporating those changes into the contract. It documents three things: the specific change in work, any adjustment to the contract price, and any adjustment to the completion deadline. Owner, contractor, and architect all must sign before it becomes part of the contract.
The process usually starts with a proposal request or a request for information. The contractor prices out the change (labor, materials, equipment, and any schedule impact) and submits the proposal to the architect, who checks that the contractor is not billing for work already included in the original contract or double-counting overhead. Once everyone agrees, the architect prepares the formal change order for signatures.
When work cannot wait for agreement on price, the architect can issue a construction change directive, which orders the contractor to proceed immediately. Cost and time are negotiated afterward and folded into a signed change order. Contractors who perform changed work on verbal instructions alone often find themselves unable to collect for it later. The paper trail matters.
Payment Protections Below the Main Contractor
Payment disputes are common enough that every state has created a statutory remedy for unpaid contractors, subcontractors, and suppliers: the mechanics lien. A mechanics lien is a legal claim against the property itself, giving the unpaid party a security interest in the real estate. If the lien is not resolved, the lienholder can ultimately force a sale of the property to recover what is owed. Filing deadlines and procedural requirements vary significantly from state to state, and missing the deadline by even one day can forfeit the right entirely.
On federal projects, mechanics liens do not apply because you cannot place a lien on government property. Instead, the Miller Act’s payment bond fills that role. Any subcontractor or supplier that has not been paid within 90 days after completing its work can file a claim against the main contractor’s payment bond. Second-tier claimants (suppliers who dealt with a subcontractor rather than the main contractor directly) must give written notice to the main contractor within 90 days of their last work. Any lawsuit on the payment bond must be filed within one year.8Office of the Law Revision Counsel. 40 USC 3133 – Rights of Persons Furnishing Labor or Material
Lien Waivers at Each Draw
Lien waivers are exchanged at every payment cycle to keep title clean. A conditional waiver is submitted with a payment request and only takes effect once the money actually arrives. An unconditional waiver takes effect the moment it is signed, regardless of whether payment has cleared. The distinction is critical: signing an unconditional waiver before the check clears means giving up lien rights with nothing in hand. Experienced subcontractors submit conditional waivers with each draw request and only sign unconditional waivers after the deposit posts.
Disputes and Ending the Contract
Construction contracts almost always include a dispute resolution clause specifying whether disagreements go to arbitration or litigation. Arbitration is private and typically faster than a lawsuit, which appeals to owners who do not want project disputes playing out in public court records. The tradeoff: arbitrator fees can be substantial, discovery is usually limited, and the right to appeal is nearly nonexistent. Litigation preserves broader discovery rights and appellate options but can drag on for years.
Termination provisions come in two varieties. Termination for cause happens when one party materially breaches the contract, such as abandoning the project, falling dangerously behind schedule, or repeatedly delivering defective work. The non-breaching party typically must provide written notice and a window to cure the problem before pulling the trigger. Termination for convenience allows the owner to end the contract without proving any fault, usually in exchange for paying the contractor for completed work plus a percentage (often around 10%) for overhead and profit on the unfinished portion.
Owners sometimes terminate for cause and then discover the grounds were shakier than they thought. Many contracts include a conversion clause: if a termination for cause is later found to be wrongful, it automatically converts to a termination for convenience, capping the owner’s exposure. Courts have enforced these clauses when the error was procedural, such as failing to give proper cure notice, but have refused to apply them when the owner acted in bad faith, such as manufacturing a default to escape a contract that became inconvenient.