When obtaining General Liability insurance for your business, it is not only important to make sure you have the proper limits/coverages, but that you are covered for Professional Liability as well.
Professional liability insurance, but more commonly known as errors & omissions (E&O), is a form of liability insurance that helps protect professional advice- and service-providing individuals and companies from bearing the full cost of defending against a negligence claim made by a client, and damages awarded in such a civil lawsuit. The coverage focuses on alleged failure to perform on the part of, financial loss caused by, and error or omission in the service or product sold by the policyholder.
An example of where a PL claim could occur: A client wants to hire your company to provide security guards for their event. You suggest to the client 4 guards will be sufficient to cover the job. It turns out 4 guards is not enough, and an incident occurs. The client will most likely try and sue to cover damages/losses caused.