ISO Form (Insurance Services Office)

Cornerstone Cabinetry LLC, a 9-employee custom millwork shop in Ohio, buys a commercial general liability policy built on the ISO CG 00 01 occurrence form — the same standardized wording used by most carriers. Because the policy uses a filed ISO form rather than a proprietary manuscript form, Cornerstone's broker can compare three quotes apples-to-apples: Carrier A at $4,200, Carrier B at $4,650, and Carrier C at $3,980. All three carry a $1,000,000 per-occurrence limit, a $2,000,000 general aggregate, a $2,000,000 products-completed operations aggregate, $100,000 fire damage legal liability, and $5,000 medical payments, with a $500 property-damage deductible.

Mid-term, a finished kitchen island Cornerstone installed collapses, injuring a homeowner and destroying $18,000 of appliances. The homeowner sues for $300,000. Because the ISO form's insuring agreement responds on an occurrence basis, the carrier defends the suit: defense costs reach $22,000 and are paid outside the limit, the bodily-injury settlement lands at $85,000, and the property damage adds $18,000 — a total $103,000 insured loss against a policy that cost under $4,200. Cornerstone had also paid a $600 endorsement to add its general contractor as an additional insured, which routed the GC's $40,000 defense tender back to Cornerstone's standardized ISO coverage instead of the GC's own policy.