Errors and Omissions Insurance coverage is a form of business liability insurance coverage for professionals such as insurance agents, architects, real estate agents, accountants, lawyers and surveyors. Also known as E and O Insurance, or professional liability insurance, it covers professionals in the event they make a mistake or omit something that should have been included, which results in financial harm to a third party.

While not every business, or professional, requires errors & omissions insurance, it is a very good idea for anybody who offers a service to a client. This coverage is in addition to other business type liability insurance, which deals with physical or financial harm done to person or property.

Any person or company that offers a service where a mistake can be made that results in financial harm to another, needs E&O Insurance. Errors and omissions coverage is there to protect a professional from lawsuits that arise from mistakes and omissions the professional makes in the normal course of offering services to clients. The possibility of making a mistake, error or omission is ever present when a professional is offering specific services for which they are the being paid; therefore, the need for errors and omissions insurance should always be a part of the professional's insurance coverage.

Professional liability insurance, also called Professional Indemnity Insurance, protects professional practitioners such as architects, home inspectors, lawyers, physicians, and accountants against potential negligence claims made by their patients/clients. Professional liability insurance may take on different names depending on the profession. For example, professional liability insurance in reference to the medical profession may be called Medical Malpractice. Notaries public may take out errors and omissions insurance (E&O). Other potential E&O policyholders include, for example,  real estate brokers, appraisers, and website developers. There are also specific E&O policies for technology companies, such as software developers, technology consultants and other creators of technology. This coverage focuses on the failure to perform, financial loss and error or omission of the products or services sold. Additional coverage for breach of warranty, intellectual property, personal injury, security and cost of contract can be added.