Professional liability, directors and officers, employment practices and cyber policies are written on a claims-made basis, and the timing rules are strict.
Trigger. The claim must be first made against the insured during the policy period and reported as the policy requires — during the period, or within a short window afterwards in claims-made-and-reported forms.
Late notice is a coverage defence without any prejudice requirement in most jurisdictions for claims-made policies, in contrast to occurrence policies.
Notice of circumstances. Reporting facts that may give rise to a claim, before renewal, fixes the claim in the current policy year. This is the most valuable provision in these policies and the most frequently unused.
Retroactive date. Coverage excludes claims arising from acts before the stated date. Changing carriers resets it unless the new policy carries the prior date forward, which is the single most important term when moving insurers.
Prior knowledge exclusion for matters known before inception, and the application’s warranty questions, which are the basis for rescission where answered inaccurately.
Extended reporting periods. Tail coverage after the policy ends, purchased for a term. Essential on a sale, on a change of carrier, and on winding down a business.
Related claims aggregated into the year of the first, which affects limits and deductibles.