Category: Reinsurance structures · Reviewed by Matt Bartlett, Director · Founder · Last reviewed 2026-06-05
The capacity layer is the upper section of an excess of loss programme, providing peak loss protection well above the working and buffer layers. It typically prices at the lowest rate on line of the programme, reflecting low expected loss frequency, and provides material protection against tail losses.
Category: Reinsurance structures Also known as: upper layer, capacity XL Related concepts: working layer, buffer layer, top layer reinsurance
The capacity layer is so called because its purpose is to provide capacity (limit, not frequency) for very large losses. The rate on line typically falls within 1–4 per cent — reflecting low expected loss frequency — and reinstatement is typically limited to one at 100 per cent additional premium, or none at all.
Capacity layers attract a different population of reinsurers from working layers: alternative capital (ILS, sidecars), pure catastrophe reinsurers and high-capacity continental European reinsurers are typical participants. Many capacity layers are placed on a ‘one-shot’ basis without reinstatement, requiring the cedant to buy a new layer if exhausted during the year.
Capacity layer contracts are documented under the Market Reform Contract format. The legal framework is identical to lower XL layers.
Cedants size capacity layers by reference to their probable maximum loss (PML) — the loss they could expect in a 1-in-N year scenario. Solvency II Pillar 1 capital requirements explicitly model 1-in-200 year stress; cedants typically size their cat XL programmes to cover their 1-in-200 PML, with the capacity layer sitting at the top of the programme.
The capacity layer is also where ILS structures are most active: catastrophe bonds, sidecars and collateralised reinsurance frequently target the capacity layers of major cat XL programmes.
An illustrative example: a UK property cat XL programme is structured as: working £25m xs £25m, buffer £50m xs £50m, capacity £100m xs £100m. The capacity layer responds to losses between £100m and £200m, priced at 1.5 per cent rate on line (£1.5m premium) with one reinstatement at 100 per cent. The cedant’s 1-in-200 PML is modelled at £180m, so the capacity layer comfortably covers the modelled stress.
This entry is part of the Apex Insurance Wiki. Last reviewed by Matt Bartlett on 2026-06-05. Next review: 2026-12-05.
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