Errors and Omissions coverage is professional liability insurance that protects professionals against negligence and other claims initiated by his/her clients. General liability insurance policies do not cover claims arising out of business or professional practices such as negligence or misrepresentation, which is why you need E&O to protect you and your business.
InterWeb Insurance, NAPA, and CalSurance Associates are all E&O carriers that we recommend and work with on a daily basis.