• Ancillary cost insurance is commercial property insurance that pays for additional costs in excess of the normal operating costs an entity incurs to continue its operations while its property is being repaired or replaced after it has been damaged by a covered cause of loss. Additional expense coverage may be purchased in addition to or instead of business income coverage, depending on the organization’s needs. There are two forms of commercial property insurance, Inc. (ISO) that provide additional expense coverage: Business Income and Income Coverage Form (CP 00 30) and Additional Cost Coverage Form (CP 00 50).