In short
This glossary defines 60+ contractor insurance and Certificate of Insurance (COI) terms in plain English, from additional insured and primary and noncontributory to waiver of subrogation and completed operations. It is written for contractors, project managers, and office staff in California and Texas who need to read bids, COIs, and endorsements. Every term is defined by a licensed broker so you can match bid language to real coverage.
// 01 · Bid & COI essentials
Bid and COI essentials
In brief: The certificate, the endorsements, and the ACORD forms every commercial bid turns on.
These are the terms you meet first on any commercial bid packet. They cover the certificate itself, the endorsements that actually change your coverage, and the standard forms that carry the proof.
- Certificate of Insurance (COI): A one-page document, almost always ACORD 25, that proves a contractor carries the specific insurance policies and limits a project owner or general contractor required for a bid or job. The COI itself does not change coverage, it only summarises what the underlying policies already say.
- Additional Insured (AI): An endorsement that adds a third party (usually the general contractor or property owner) to the contractor's liability policy so that party shares coverage for claims arising from the contractor's work. Required by most commercial GCs in California and Texas. See our Additional Insured guide.
- Primary and Noncontributory (PNC): Endorsement language stating that the contractor's policy pays first and does not require the upstream party's policy to share in the loss. Required alongside Additional Insured on virtually every commercial bid packet. See Primary and Noncontributory.
- Waiver of Subrogation (WOS): Endorsement in which the contractor's insurer agrees not to pursue recovery from a named third party (typically the GC or owner) after paying a claim. Functionally protects the upstream party's loss history. See Waiver of Subrogation.
- ACORD 25: The standardised industry form used as the body of nearly every Certificate of Insurance. Shows policy numbers, dates, limits, and certificate holders. Issued by the broker; the underlying policy is what actually provides coverage.
- ACORD 27: The Evidence of Property Insurance form, used in lieu of an ACORD 25 when a lender or property manager only needs proof of property (not liability) coverage.
- ACORD 28: Evidence of Commercial Property Insurance, a more detailed cousin of the ACORD 27 used for commercial property loss-payee verification.
- Endorsement: A formal amendment to an insurance policy that adds, changes, or removes coverage. Endorsements, not the COI, are what actually deliver Additional Insured, PNC, WOS, or any non-default coverage.
- Named Insured: The person or entity listed on a policy's declarations page as the policyholder. Only the Named Insured has full rights under the policy; everyone else (employees, additional insureds) has more limited rights.
- Certificate Holder: The entity that receives the COI as evidence of insurance. Being a certificate holder does not make a party an additional insured, that requires the AI endorsement.
// 02 · Core coverages
Core coverages
In brief: The policies that make up a contractor's stack, from general liability to builder's risk.
These are the policies that make up a contractor's insurance stack. Most commercial bids require some combination of the coverages below.
- General Liability (GL): Insurance that pays for bodily injury, property damage, and personal or advertising injury claims arising from a contractor's operations, premises, products, or completed operations. The core policy on essentially every contractor's stack. See general liability insurance.
- Workers' Compensation (WC): State-mandated coverage paying medical bills and lost wages for employees injured on the job, in exchange for the employee waiving the right to sue. Required by California law for any business with employees; required in Texas for almost all government and many private contracts. See workers' compensation.
- Ghost Policy: A workers' compensation policy with zero payroll on the schedule, used by sole-proprietor contractors with no employees to satisfy a COI requirement. Legal in many states but contract- and carrier-dependent. Improperly used, it creates audit and contract-compliance problems. See ghost policies.
- Commercial Auto Insurance: Liability and physical-damage coverage for vehicles owned, leased, or used by a business. Personal auto policies exclude business use, so contractors hauling tools, towing trailers, or driving employees to job sites need commercial auto. See commercial auto.
- Hired and Non-Owned Auto (HNOA): Liability extension that covers vehicles a business rents, borrows, or that employees own and drive on company business. Critical for contractors who run subcontractors or have employees making errand runs in personal vehicles.
- Tools and Equipment Insurance (Inland Marine): Property coverage for tools, mobile equipment, and materials in transit or at a job site, which most General Liability policies exclude. Often called an Installation Floater when the coverage extends to materials being installed. See tools and equipment coverage.
- Contractor Surety Bond: A three-party agreement among contractor, obligee (state or owner), and surety, guaranteeing the contractor will fulfil license or contract obligations. Required by CSLB for California contractors (currently $25,000 minimum). Not insurance; it is a credit instrument. See contractor bonds.
- Commercial Umbrella / Excess Liability: A policy stacked above GL, employer's liability, and commercial auto that pays once an underlying limit is exhausted. Often the cheapest way to reach the $5M or $10M combined limits commercial bids demand. See umbrella and excess.
- Builder's Risk / Course of Construction (COC): Property insurance covering a structure under construction against fire, theft, vandalism, and weather. Pays for the materials, fixtures, and labor invested up to a date of loss. See builder's risk.
// 03 · Policy mechanics
Policy mechanics
In brief: Limits, deductibles, defense costs, and the moving parts that decide what a policy actually pays.
Once you have a policy, these terms govern how much it pays, what you pay first, and how legal defense is handled.
- Per Occurrence Limit: The maximum a liability policy will pay for any single claim. Typical contractor minimums on commercial bids are $1,000,000 per occurrence.
- Aggregate Limit: The maximum a liability policy will pay across all claims in a policy term. California commercial bids typically demand $2,000,000 aggregate against a $1,000,000 per-occurrence.
- Aggregate Erosion: The depletion of the aggregate limit by paid claims, defense costs, or both during the policy term. If aggregate erodes below a bid requirement mid-term, the contractor can be in default on active jobs.
- Products-Completed Operations: GL coverage for bodily injury or property damage arising after a contractor's work is completed and turned over. Roofers and other trades whose work is judged years after the fact rely heavily on this coverage.
- Personal and Advertising Injury: GL coverage for non-physical liabilities such as libel, slander, copyright infringement in advertising, and wrongful eviction. Less common in contractor claims but always part of standard GL.
- Bodily Injury: Physical injury, sickness, or disease to a person, including death. The most common contractor GL claim category.
- Property Damage: Physical injury to tangible property of others, including loss of use. The other dominant contractor GL claim category.
- Defense Costs (Inside vs. Outside Limits): Legal expenses an insurer pays to defend a covered claim. Inside the limits means defense costs erode the policy limit; outside the limits means defense is paid in addition to the limit. Outside-the-limits is more contractor-friendly.
- Deductible: Amount the insured pays out of pocket per claim before the insurer pays. Distinct from a Self-Insured Retention (SIR), where the insured handles the claim itself up to the SIR amount.
- Self-Insured Retention (SIR): A dollar amount the insured must pay out of pocket before the insurer's obligation begins, including the insured's own defense. Common on high-hazard contractor policies.
- Premium: The cost of an insurance policy, typically expressed as an annual figure. Contractor GL premium is driven mostly by trade class code, payroll or gross receipts, claims history, and limits.
- Tail / Extended Reporting Period: An add-on to a claims-made policy that extends the window during which a covered claim can be reported after the policy expires. Relevant for any contractor whose work could surface a problem years later.
// 04 · Carriers & markets
Carriers and markets
In brief: Who carries the risk, who is admitted, and where surplus-lines coverage comes from.
Not every policy comes from the same kind of insurer. These terms describe who carries the risk and which market your coverage is placed in.
- Carrier: The insurance company that actually issues the policy and pays claims. Brokers are intermediaries; carriers carry the risk.
- Admitted Carrier: An insurer licensed in a given state, subject to that state's rate filings and guaranteed by the state guaranty fund. Most standard contractor policies are admitted.
- Non-Admitted / Surplus Lines (E&S): A carrier not licensed in the state, accessed through a wholesale broker for risks the admitted market will not write. Not guaranteed by the state guaranty fund; rates and forms are less regulated. Common for high-hazard roofing, demolition, or new contractors.
- Wholesaler / MGA: A specialty broker that retail brokers go through to access surplus-lines and program markets. A contractor's retail broker may quote with a wholesaler when the standard market declines the risk.
- AM Best Rating: A credit-style rating from A++ to D measuring an insurance carrier's financial strength. Most commercial bid packets require carriers with an AM Best rating of A- or better.
- Risk Purchasing Group (RPG): A group of similar businesses that buy liability insurance jointly under the federal Liability Risk Retention Act. Sometimes available to specialised trade groups (roofers, plumbers) at better rates than open-market quotes.
// 05 · WC classification & audit
Workers' comp classification and audit
In brief: Class codes, X-Mod, loss runs, and the 1099 trap that drives most audit surprises.
Workers' compensation premium is rated on payroll and job duties, then reconciled at audit. These are the terms that decide what you owe at year-end.
- Premium Audit: Year-end reconciliation of actual exposure (payroll, receipts, subcontractor cost) against the estimates used to bind the policy. Results in either an additional premium owed or a refund.
- Class Code: A numeric code that categorises a contractor's work for rating purposes. In California, WC uses WCIRB class codes; most other states (and GL nationally) use NCCI or ISO codes.
- WCIRB (California): Workers' Compensation Insurance Rating Bureau of California, the agency that classifies trades and computes experience modifiers for California WC policies.
- NCCI: National Council on Compensation Insurance, the equivalent of WCIRB for most states outside California. Texas is one of the few states that uses NCCI but allows non-NCCI deviations.
- Experience Modifier (X-Mod / EMR): A multiplier (1.00 = average) applied to a contractor's workers' compensation premium based on three prior years of claims history. A 0.85 X-Mod means 15% less than industry-average premium; 1.20 means 20% more. Many commercial bids demand an X-Mod below 1.00.
- Loss Runs: A carrier-issued report listing every claim filed under a policy over a prior period (usually 3 to 5 years). Required by virtually every new carrier before binding coverage.
- Loss Ratio: Total claims paid (and reserved) divided by premium earned, expressed as a percentage. Underwriters use it to judge whether a contractor's account has been profitable.
- Pay-As-You-Go Workers' Comp: A WC payment structure where premium is calculated and debited each payroll run rather than estimated annually. Reduces audit surprises but adds a small reporting cost.
- 1099 vs. W-2: An IRS classification distinction with major workers' compensation implications. A worker paid on a 1099 may still be deemed an employee by the state (California's ABC test, Texas's right-of-control test) and trigger WC obligation; relying on 1099 status to avoid WC is the number-one audit-loss surprise for contractors.
// 06 · State regulators (CA & TX)
State regulators in California and Texas
In brief: The boards and bureaus that license contractors and regulate insurance in our two states.
These are the California and Texas agencies that license contractors, regulate insurance, and decide disputes. See our California and Texas service-area pages.
- CSLB: California Contractors State License Board, the state agency that licenses construction contractors in California and enforces a minimum $25,000 contractor's bond and (for contractors with employees) workers' compensation.
- TDI: Texas Department of Insurance, the state regulator for insurance in Texas, including contractor general liability, commercial auto, and (for most public projects) workers' compensation.
- WCAB (California): Workers' Compensation Appeals Board, the California adjudicatory body that hears disputes about workers' compensation benefits and coverage.
- Sole Proprietor Exemption: In California, an actively licensed contractor with no employees may opt out of carrying workers' comp by filing the CSLB exemption, but a GC can still contractually require WC for the job. In Texas, sole proprietors may also self-exempt, with the same contract caveats.
- Prevailing Wage / Public Works: On public projects in California and Texas, contractors must pay the state-determined prevailing wage and certify compliance. Affects both payroll classification for WC and certified payroll reporting.
// 07 · Contracts & project structures
Contracts and project structures
In brief: Indemnification, subcontractors, OCP, and the wrap-up programs used on large jobs.
Finally, these terms describe how risk is allocated by contract and how insurance is structured on larger projects.
- Indemnification / Hold Harmless: A contract clause in which one party agrees to pay for the losses of another. California and Texas both restrict the breadth of indemnification a contractor can be forced to grant; California's anti-indemnity statute is among the strictest in the US.
- Subcontractor: A contractor hired by a higher-tier contractor (the GC or a prime sub) to perform a portion of the work. Subs' insurance status (or lack of it) flows up to the GC's claims experience via additional-insured and indemnity clauses.
- Owners' and Contractors' Protective (OCP): A standalone liability policy purchased by a GC (or owner) covering its own liability for the operations of a specific subcontractor. Used in lieu of, or in addition to, Additional Insured language.
- Wrap-Up (OCIP / CCIP): A single insurance program covering an owner (OCIP) or contractor (CCIP) and most or all enrolled subs on a defined project. Common on large commercial and public works jobs.
Need an endorsement, COI, or policy explained in plain English for your specific bid? We respond within one business hour during California and Texas business hours.