General Liability vs Professional Liability in Ontario: Key Differences

A customer trips on a wet floor in your office lobby and fractures a wrist. Your CGL policy covers that. An engineering calculation error in a bridge design costs a municipality $300,000 in repairs. Your CGL policy does not cover that. Same business, same building, two fundamentally different risks that require two fundamentally different insurance policies.

This is where most Ontario business owners get tripped up. They assume their commercial general liability (CGL) policy is a catch-all. It is not. CGL and professional liability (also called errors and omissions, or E&O) protect against entirely different categories of risk. Understanding where one ends and the other begins can mean the difference between a covered claim and a six-figure out-of-pocket loss.

CGL Insurance: Protection Against Physical Risks

Commercial general liability insurance is the bedrock of business coverage in Ontario. It protects your business when your operations cause physical harm to someone else or damage their property.

A standard CGL policy in Canada follows the Insurance Bureau of Canada (IBC) form and includes three main coverage parts:

Coverage A: Bodily Injury and Property Damage. This is the core of CGL. It pays when a third party is injured on your premises, by your products, or as a result of your business operations. A delivery driver backs into a client's fence. A customer slips on ice outside your storefront. A product you sold causes an allergic reaction. Coverage A responds to all of these.

Coverage B: Personal and Advertising Injury. This covers non-physical harms like libel, slander, wrongful eviction, false arrest, and copyright infringement in your advertising. If a competitor sues you alleging your ad campaign copied their tagline, Coverage B applies.

Coverage C: Medical Payments. This pays minor medical expenses for people injured on your premises regardless of fault. It is designed to handle small claims quickly before they escalate into lawsuits.

CGL also covers your legal defence costs. If someone sues your business for a covered claim, your insurer has a duty to defend you, and defence costs are typically paid in addition to the policy limits.

What CGL Does Not Cover

CGL has some critical exclusions that every business owner should understand:

• Professional services. If a client suffers financial loss because of your advice, your design, or your professional judgment, CGL will not respond. This exclusion is why professional liability insurance exists.
• Employee injuries. Workers injured on the job are covered by Ontario's Workplace Safety and Insurance Board (WSIB), not your CGL policy.
• Your own property. CGL covers damage to other people's property, not your own business assets.
• Intentional acts. Deliberate harm is never covered.
• Automobile-related claims. These fall under commercial auto insurance.

In Ontario, most commercial contracts and municipal tenders require a minimum of $2 million in CGL coverage. For contractors and construction trades, this has become a de facto requirement to get on a job site, even though no single Ontario statute mandates it for all businesses.

Professional Liability Insurance: Protection Against Financial Harm From Your Services

Professional liability insurance, also called errors and omissions (E&O) insurance, covers a completely different category of risk. It responds when your professional services, advice, or expertise causes a client to suffer financial loss.

Think of it this way: CGL covers what your business does physically. Professional liability covers what your business knows and advises.

What Professional Liability Covers

• Errors. An accountant transposes digits on a tax filing, triggering a reassessment and penalties for the client.
• Omissions. A lawyer misses a limitation period deadline, and a client loses the right to pursue a valid claim.
• Negligent advice. A consultant recommends a software platform that proves incompatible with a client's systems, costing thousands in lost productivity.
• Breach of duty. An architect's design fails to meet building code requirements, delaying a project and increasing costs.
• Legal defence. Even if the claim is baseless, your E&O policy covers the cost of defending you.

Professional liability insurance is almost always written on a claims-made basis. This is a critical difference from CGL, which typically uses an occurrence trigger. With a claims-made policy, coverage is triggered when the claim is reported to the insurer during the policy period, not when the error originally occurred. This means:

• You need to maintain continuous coverage without gaps.
• Your policy's retroactive date determines how far back coverage extends.
• If you cancel or switch carriers, you may need an extended reporting period (sometimes called tail coverage) to cover claims reported after cancellation for errors that happened while you were insured.

Your broker should walk you through these mechanics before you buy, because a gap in claims-made coverage can leave you exposed for past work.

Ontario Professions That Legally Require Professional Liability Insurance

Several regulated professions in Ontario make professional liability insurance mandatory. If you belong to one of these groups, you cannot legally practise without it.

Lawyers. The Law Society of Ontario requires all practising lawyers to carry professional liability insurance through the Lawyers' Professional Indemnity Company (LAWPRO). Lawyers who are not in private practice — such as in-house counsel, government lawyers, or those employed by Legal Aid Ontario clinics — may be eligible for an exemption, but even exempt lawyers receive reduced coverage of $250,000 per claim at no charge.

Architects. The Ontario Association of Architects (OAA) requires every holder of a Certificate of Practice to purchase mandatory professional liability insurance from Pro-Demnity Insurance Company, the OAA's wholly owned subsidiary. There is no option to use a different carrier for the mandatory minimum.

Engineers. Professional Engineers Ontario (PEO) requires engineers who hold a Certificate of Authorization (C of A) — meaning they offer engineering services directly to the public — to either carry professional liability insurance or provide compulsory disclosure to each client stating they are uninsured. The Ontario Society of Professional Engineers (OSPE) offers group professional liability insurance programs for members.

Accountants. CPA Ontario requires all firms engaged in public accounting to maintain professional liability insurance meeting prescribed minimums: $1 million for sole practitioners, $1.5 million for two- or three-member firms, and $2 million for firms with four or more members.

Insurance brokers. The Registered Insurance Brokers of Ontario (RIBO) requires every brokerage to maintain E&O coverage of at least $3 million per claim and $6 million in aggregate. Policies must be underwritten by insurers licensed in Ontario and include special RIBO endorsements.

Regulated health professions. Under the Regulated Health Professions Act, Ontario's health regulatory colleges set professional liability insurance requirements for their members. For example, the College of Nurses of Ontario requires $1 million per claim for RNs and RPNs, while the College of Occupational Therapists requires $5 million per incident. Requirements vary by college.

Even if your profession does not legally mandate E&O coverage, your clients or contracts may require it. IT consultants, marketing agencies, graphic designers, financial advisors, and many other service providers carry E&O insurance because their clients demand proof of coverage before signing an agreement.

Side-by-Side Comparison

| Feature | CGL | Professional Liability (E&O) | |---|---|---| | Protects against | Bodily injury, property damage, advertising injury | Errors, omissions, negligent advice, breach of duty | | Type of harm covered | Physical harm to people or property | Financial loss to clients | | Coverage trigger | Occurrence (typically) | Claims-made (almost always) | | Legal defence | Included, duty to defend | Included | | Common limits in Ontario | $2M–$5M per occurrence | Varies by profession and risk | | Required by | Most contracts, leases, tenders | Regulatory colleges, client contracts | | Does NOT cover | Professional errors, employee injuries, your own property | Bodily injury, property damage, criminal acts |

When You Need Both Policies

Many Ontario businesses need both CGL and professional liability. The two policies are not interchangeable and they do not overlap. If your business involves any combination of physical operations and professional advice or services, a single policy type will leave gaps.

A consulting engineer needs CGL for premises liability (someone slipping in the office) and professional liability for design errors that cause financial loss.

An IT services company needs CGL for any technician visits to client sites (accidental property damage) and E&O for software implementation failures or data migration errors.

A [healthcare practice](/commercial/healthcare-insurance) needs CGL for patient injuries unrelated to treatment (tripping in the waiting room) and professional liability for clinical negligence claims.

A marketing agency needs CGL for events it hosts and E&O for a campaign strategy that a client alleges caused lost revenue.

The general rule: if your business gives advice, creates designs, manages projects, handles data, or provides any service where your expertise and judgment matter, you should carry professional liability alongside your CGL.

How to Get the Right Coverage

The easiest path to getting this right is working with a broker who understands both policy types and how they interact. Here is what to focus on:

Assess your exposures honestly. List every service your business provides. For each one, ask: could a mistake here cause a client financial harm? If yes, that is a professional liability exposure.

Check your contracts. Review your client agreements, lease, and any tender requirements. Many will specify minimum insurance limits for both CGL and E&O.

Understand claims-made mechanics. If you are buying professional liability for the first time, discuss the retroactive date with your broker. If you are switching carriers, make sure there is no gap in your claims-made coverage.

Do not assume you are too small. A sole-proprietor consultant faces the same professional liability exposure as a large firm. The difference is that a single uninsured claim could be business-ending for a small operation.

Review annually. As your business grows, your services evolve, and your contracts change, your coverage should keep pace.

If you are unsure whether your current policies cover all your risks, request a no-obligation quote or call us at (905) 576-7770. We represent over a dozen carriers and can compare options to find the right fit for your business.