Excess Clause

An excess clause is a form of other insurance clause stating that the policy will respond only after every other policy covering the loss has paid its limits. Until the underlying coverage is exhausted, the excess-clause policy contributes nothing; once that primary limit is gone, it "drops down" to cover the remainder up to its own limit. This differs from pro rata sharing, where all policies contribute simultaneously in proportion to their limits. Excess clauses are common in umbrella policies, auto policies covering non-owned exposures, and coverage granted to additional insureds.

For a small-business buyer, understanding excess wording tells you the order in which your coverage responds and helps you avoid paying for redundant limits. When you rent equipment or drive a vehicle you do not own, your policy often becomes excess over the owner's insurance, meaning the owner's coverage pays first. This layering matters for pricing and for meeting contract requirements: if a client insists your coverage be primary and noncontributory, an excess clause would violate that demand because it forces the client's policy to pay first. Reading the clause tells you whether you are the first or last line of defense.

A practical nuance involves horizontal vs. vertical exhaustion. When multiple excess layers exist, courts must decide whether all primary policies across every applicable program must be exhausted first (horizontal) or only the tower directly beneath the excess policy (vertical). The answer changes how quickly your excess coverage is triggered. Two competing excess clauses can also be deemed mutually repugnant, forcing the carriers to prorate. Never assume an excess-clause policy will respond early; confirm what must be exhausted before it engages, and coordinate with any self-insured retention you carry.