Work out reinsurance share instantly with clear inputs, formula shown and shareable results.
Under a surplus treaty the insurer keeps one line — its retention — and cedes the surplus up to a stated number of lines. The retained proportion of every risk written within capacity is retention divided by the sum insured, and claims are shared in the same proportion.
Treaty capacity
Capacity = Retention x (1 + Number of lines)
Retained share
Retained % = Retention / Sum insured placed
Claim split
Ceded claim = Claim x (1 - Retained share)
Indicative estimate only. Fees, entitlements, limits and formulas vary by jurisdiction, statute, policy wording and the facts of the case. This is not legal, tax, insurance or financial advice — confirm with a qualified professional or the relevant authority.
One line equals the insurer's retention. A nine-line treaty therefore provides capacity of ten times the retention including the retention itself.
Quota share cedes a fixed percentage of every risk. Surplus cedes only the amount above retention, so the insurer keeps 100% of small risks.