Quota-Share Reinsurance
Definition
Quota-share reinsurance is proportional reinsurance in which the insurer cedes a fixed percentage of each policy in a defined book to the reinsurer. The reinsurer receives that percentage of the premium, usually less a ceding commission that compensates the insurer for acquiring and servicing the business, and pays the same percentage of every loss. The reinsurer shares in all results, small claims and large ones, rather than only losses above a threshold.
Why it matters
A quota share gives the capital provider the full underwriting result of a book: the premium margin, the expenses and every loss. That makes it the clearest way to share an insurer's economics and the hardest to analyze from outside, because results depend on pricing adequacy and on how claims develop over years. The ceding commission and how losses are reserved decide most of the outcome.
Common misconceptions
- •Quota share does not cap the reinsurer's loss at a low layer. It pays its share of every loss.
- •A high premium share is not all profit; the ceding commission and losses come off first.
- •A booked loss ratio early in a treaty is often an estimate, not experience.
- •The label is only a starting point. Investor outcomes usually depend on the governing documents, cash-flow priority, valuation policy, disclosure quality, and manager discretion surrounding the term, not just the shorthand definition used in marketing materials.
Technical details
Worked example
Book: $100 million of written premium; quota share 30%.
Ceded premium: $30 million; ceding commission 25%: $7.5 million back to the insurer.
Losses on the book: $60 million (60% loss ratio); reinsurer pays 30%: $18 million.
Reinsurer's underwriting result before its own expenses: $30.0m - $7.5m - $18.0m = $4.5 million, plus income on collateral.
Terms to check
Ceding commission, fixed or sliding with the loss ratio.
Event or aggregate caps on the reinsurer's share.
Underwriting year covered and run-off of claims.
Collateral and trust arrangements if the reinsurer is unrated.
How investors apply the term
Investors usually apply this term by tying the definition back to the controlling documents and then asking which cash flows, rights, restrictions, or valuation assumptions it changes. A useful review looks at the term alongside fees, leverage, liquidity, reporting frequency, and manager discretion rather than treating it as a standalone concept.
The practical diligence test is simple: identify who benefits if the assumption is wrong, who has control when conditions change, and what evidence the investor receives after closing. Terms that cannot be reconciled to documents, cash movements, and monitoring data should be treated as marketing shorthand until proven otherwise.
Frequently asked questions
- What is a ceding commission?
- A payment from the reinsurer back to the insurer, expressed as a percentage of ceded premium, for the costs of writing the business. It reduces what the reinsurer keeps and is a large driver of quota-share economics.
- Why do insurers buy quota share?
- To write more business than their capital allows, to reduce the capital a line requires, or to share a new or volatile line with a partner who takes the same results.
- Who takes quota shares from outside the industry?
- Sidecars and ILS vehicles. RenaissanceRe's Fontana takes a whole-account quota share of its casualty and specialty book; tokenized reinsurance products have also used quota-share treaties of U.S. insurers as their underlying risk.