A form of insurance coverage that replaces business income lost as a result of an event that interrupts the operations of the business, such as fire or a natural disaster. Business interruption insurance is not sold as a separate policy, but is either added to a property/casualty policy or included in a comprehensive package policy. Business interruption insurance premiums (or at least the additional cost of the rider) are deductible as ordinary business expenses. This type of policy pays out only if the cause of the business income loss is covered in the underlying property/casualty policy. The amount payable is usually based on the past financial records of the business.