The split is about the kind of harm. A commercial general liability (CGL) policy is written for bodily injury, property damage and personal and advertising injury coming out of your premises, operations, products and completed work. Professional liability is written for financial loss caused by an error or omission in your professional services, the kind of claim where a drawing, a recommendation or a software build was wrong and the client lost money. A CGL claim still needs injury, damage or an advertising-type offense, so that loss does not fit, and insurers can add an endorsement that excludes professional services. Most CGL policies are occurrence forms; most professional liability policies are claims-made, which changes how you handle carrier changes and retirement. If you both do physical work and give advice, plan on carrying both.
What general liability responds to
IRMI describes the commercial general liability policy as protecting a business against liability claims for bodily injury and property damage arising out of premises, operations, products and completed operations, plus personal and advertising injury. ISO introduced it in 1986.
A customer trips in your shop, a crew drops a beam through a client’s roof, or a competitor says your ad libeled them: those are GL claims. The advertising side includes libel, slander, invasion of privacy and copyright infringement in your advertising. More on general liability insurance.
What professional liability (E&O) responds to
Professional liability is built for a different kind of loss. IRMI defines it as coverage designed to protect professionals and businesses from errors and omissions in performing their professional services, and notes that most policies cover only economic or financial loss, leaving bodily injury and property damage to the CGL.
Think of an engineer’s drawings that have to be redone or a software build that does not do what the contract said. Nobody is hurt, nothing is broken, but the client lost money. IRMI also notes that defense costs reduce the professional liability limit, unlike a standard CGL. More on professional liability insurance.
The professional services exclusion on the CGL
An IRMI commentary notes that the ISO CGL does not automatically exclude professional services; it has to be endorsed to take them out. Once an exclusion is attached, even an injury claim tracing back to professional services can fall outside the CGL. The endorsements it covers:
- CG 22 43, Exclusion – Engineers, Architects or Surveyors Professional Liability, defines professional services to include preparing or approving maps, shop drawings, opinions, reports, surveys, change orders, drawings and specifications, plus supervisory, inspection, architectural or engineering activities.
- CG 22 79, Exclusion – Contractors – Professional Liability, excludes professional services but carves back construction means, methods, techniques, sequences and procedures.
- CG 22 80, Limited Exclusion – Contractors – Professional Liability, is aimed at design-build contractors. It excludes professional services only in connection with construction not performed by or on behalf of the insured; design work done as part of the insured’s own construction is not excluded.
The same commentary notes courts have found that a failure to warn about a known danger does not depend on rendering professional services. Check your CGL’s endorsement schedule.
Occurrence vs claims-made
An occurrence policy covers claims arising out of damage or injury that took place during the policy period, regardless of when the claim is made; IRMI notes most CGL insurance is written that way. A claims-made policy is triggered when a claim is made against you during the policy period, regardless of when the wrongful act happened, except that if the policy carries a retroactive date the act must have happened on or after it. Most professional, E&O, directors and officers, and employment practices liability is written claims-made.
A retroactive date eliminates coverage for wrongful acts before that date, so when you move your E&O to a new carrier, ask it to keep your original retroactive date, or claims from earlier work can fall outside the new policy. When you close the business or retire, an extended reporting period, often called the tail, lets a claim made after the policy ends be treated as if it came in during the policy period, as long as the act happened while the policy was in force. Claims-made vs. occurrence, in detail.
Who needs both
Many operations produce both kinds of claims.
- Design-build contractors. An IRMI commentary says the CGL is not adequate to cover the expanded liabilities design-build contractors assume. Leaning on the design firm’s policy has holes: if that firm is out of business when a claim arrives, its claims-made policy likely leaves nothing. Contractor insurance starts with GL; design responsibility adds E&O.
- Consultants and professional firms. IRMI names accountants and attorneys, real estate brokers and consultants; Texas adds engineers and IT consulting alongside trades like electrical and air conditioning work.
- Technology firms. Tech E&O is designed to cover providers of technology services or products; IRMI notes cyber and privacy insurance is instead intended to protect consumers of technology.
- Medical. Medical malpractice insurance covers the acts, errors and omissions of physicians, surgeons and allied healthcare providers. A slip in the waiting room is a GL claim; a missed diagnosis is not. More on medical malpractice insurance.
Requirements vary by state. Texas, for example, requires home day care centers, HVAC installers, plumbers and real estate inspectors to carry professional liability.
Contracts and what underwriters ask
A client agreement or project specification may call for GL at one limit and professional liability at another, and your certificate has to show both. On design-build jobs, an IRMI commentary describes owners requiring a dedicated professional liability limit for the project. Send me the insurance article before you sign; a certificate of insurance can only show what the policies say.
A professional liability application is built around a narrative of your services, and only the services you describe are considered for coverage, so “see website” is not an answer. Carriers ask for the past twelve months of revenue plus a projection for the next twelve because the policy is normally rated on revenues, along with headcount and known claims or incidents. The application is a warranty or representation; policies have been rescinded over what was included or omitted.
Common questions
Does general liability cover professional mistakes?
Not when the loss is purely financial. A CGL claim has to involve bodily injury, property damage or personal and advertising injury, and insurers can attach an ISO exclusion such as CG 22 43 or CG 22 79 that takes professional services claims off the CGL.
Is E&O the same as professional liability?
In practice, yes. Texas regulators note professional liability is sometimes called errors and omissions, and IRMI defines E&O as protection against liability for an error or omission in performing professional duties. For physicians and other healthcare providers it is sold as medical malpractice.
Can I carry just one of them?
It depends on what you do. The SBA suggests GL for any business and professional liability for businesses that provide services to customers. If you only do physical work, GL may be the whole picture; if you give advice, design or write code, the CGL will not reach the financial-loss claims.
Why is professional liability claims-made when GL is occurrence?
That is how the two markets are mostly built. Most CGL insurance triggers on when the injury or damage happened; most professional, E&O, D&O and EPL policies trigger on when the claim is made, subject to any retroactive date. That means watching the retroactive date at every carrier change and looking at a tail when you stop.
Do contractors need professional liability?
Those who take on design responsibility usually do. An IRMI commentary says the CGL is not adequate for a design-builder’s expanded liabilities, and contractor CGLs may carry CG 22 79, which excludes professional services, or the narrower CG 22 80. A contractor who only builds to someone else’s plans has a much smaller professional exposure, and the underwriter will ask.
Sources
- IRMI glossary: commercial general liability (CGL) policy
- IRMI glossary: advertising injury
- IRMI glossary: professional liability
- IRMI glossary: errors and omissions (E&O) insurance
- IRMI expert commentary (Craig Stanovich, 2014): the CGL and the professional liability exclusion
- IRMI glossary: occurrence policy
- IRMI glossary: claims-made policy
- IRMI glossary: retroactive date
- IRMI glossary: extended reporting period (ERP)
- IRMI glossary: tail coverage
- IRMI expert commentary (Ann Hickman, 2002): insuring design-build risks
- IRMI expert commentary (Jeff Slivka, 2013): professional liability requirements for design-build projects
- IRMI glossary: technology errors and omissions insurance
- IRMI glossary: medical malpractice insurance
- Texas Department of Insurance: FAQ, professional liability insurance
- U.S. Small Business Administration: get business insurance
- Insurance Journal (Rocio L. Orta, 2005): analyzing the professional liability application
General information about general liability and professional liability (E&O) insurance as of October 2026, not legal advice; the policy forms, endorsements and the contract you sign control. Coverage depends on underwriting and the terms, conditions and exclusions of the policy actually issued.