Complete GuideUpdated March 2026

Treaty Reinsurance Pricing

From burning cost to exposure rating — and how AI agents are eliminating the manual data gathering that consumes 70% of every pricing cycle.

SP
Shen Pandi
Founder & CEO, Reinsured.AI · Ex-McKinsey, Deloitte, EY

What is Treaty Reinsurance Pricing?

Treaty reinsurance pricing is the process by which a reinsurer calculates the premium it requires to provide coverage to a cedent under a treaty arrangement. Unlike facultative reinsurance — which prices individual risks — treaty pricing covers an entire portfolio of risks under agreed terms.

The pricing process is data-intensive. A reinsurer must analyse years of historical loss experience, assess current exposure levels, apply actuarial adjustments for trend and development, and benchmark against market rate-on-line levels — all before making a pricing decision.

Until recently, assembling all the necessary data could take a pricing actuary or underwriter 2–5 days per treaty renewal. AI agents now automate the data gathering and calculation steps entirely, leaving actuaries to focus on judgement rather than spreadsheet construction.

Treaty Pricing Methods

Burning Cost

XoL treaties with 5+ years of experience

Calculates the historical rate of loss within the reinsurance layer. Actual layer losses are divided by the subject premium for each year of the experience period, then trended, developed for IBNER, and loaded for expenses and profit.

Burning Cost = Layer Losses ÷ Subject Premium × 100

Exposure Rating

New programmes, low-frequency classes

Prices the treaty based on the underlying risk profile rather than historical loss experience. Industry loss severity curves are applied to the cedent's exposure distribution to estimate expected losses within the reinsurance layer.

Layer Loss Cost = ∑ (Exposure × Layer Loss Factor from ILF curve)

Blended Rating

Most standard XoL renewals

Combines burning cost and exposure rating with credibility weighting based on the volume and quality of loss experience. More weight given to burning cost when experience is credible; exposure rating dominates when experience is sparse.

Blended Rate = (Z × Burning Cost) + ((1−Z) × Exposure Rate)

Proportional Commission Adequacy

Quota share and surplus share treaties

For proportional treaties, pricing focuses on the adequacy of the ceding commission relative to the cedent's expense ratio, combined ratio, and profit commission structure.

Break-even Commission = 100% − Expected Loss Ratio − Reinsurer Expenses

Data Requirements for Treaty Pricing

The completeness and quality of cedent data is the single biggest driver of pricing accuracy. The following table shows what is needed and how AI agents accelerate collection:

Data TypeMin. PeriodManual TimeWith AI
Subject Premium Income (SPI)5–10 years30 min2 min
Paid & incurred loss history5–10 years2–4 hours15 min
Large loss detail5–10 years1–2 hours10 min
Development triangles10+ years3–6 hours20 min
Exposure schedule (SI dist.)Current year1–2 hours10 min
Geographic breakdownCurrent year30 min5 min
Reinstatement provisionsTreaty terms15 min2 min

AI Automation in Treaty Pricing

The Reinsured.AI pricing agent handles the full data pipeline — from raw cedent documents to a populated pricing template — in under two hours:

01
Ingest any format

Upload bordereaux, loss runs, ACORD forms, or proprietary spreadsheets. The agent extracts structured data from any layout without templates or configuration.

02
Validate and cleanse

Cross-references extracted figures against prior-year data, flags inconsistencies, and identifies IBNER patterns in development triangles automatically.

03
Calculate burning cost

Runs year-by-year burning cost at each attachment point, applies trend and development factors, and produces a technical rate recommendation.

04
Generate pricing memo

Produces a structured memo with full data sources, assumptions, sensitivity tables, and market ROL benchmarks — ready for actuary sign-off.

Proportional vs Non-Proportional Pricing

Proportional

Quota ShareSurplus Share
Key Metric
Ceding Commission
Pricing Question

Is the commission adequate given the cedent's loss ratio, expense base, and profit commission structure?

AI Automation

Auto-extract historical combined ratios, model commission adequacy across loss ratio scenarios, flag adverse development.

Non-Proportional

Per Risk XoLPer Occurrence XoLAggregate Stop Loss
Key Metric
Rate on Line (ROL)
Pricing Question

What premium is required to cover expected layer losses plus expenses and target profit — as a percentage of the limit?

AI Automation

Burning cost calculation, ILF overlay, IBNER adjustment, reinstatement modelling, and ROL benchmarking.

Market Rate on Line Benchmarks

ClassLayerTypical ROL RangePricing Method
Property CAT1st loss layer8–15%Exposure / Burning Cost
Property CATUpper layers2–6%Exposure Rating
Liability XoLWorking layer10–20%Burning Cost
Marine XoL1st layer5–12%Burning Cost
Motor XoLPer risk3–8%Burning Cost
Quota Share (Property)N/ACommission 25–35%Commission Adequacy

Indicative ranges only. Actual pricing depends on loss experience, exposure profile, and prevailing market conditions.

Frequently Asked Questions

What is burning cost in treaty reinsurance pricing?

Burning cost is the most common method for pricing excess of loss reinsurance treaties. It calculates the historical rate of loss within a specific reinsurance layer by dividing the actual losses attaching to the layer by the total subject premium over the experience period (typically 5–10 years). The result is adjusted for trend, development, and IBNER to produce a projected burning cost rate.

What is exposure rating in reinsurance?

Exposure rating prices a reinsurance treaty based on the underlying risk characteristics rather than historical loss experience. It uses industry loss curves to estimate the expected loss within the reinsurance layer based on the cedent's premium volume, line of business, and geographic concentration. Exposure rating is preferred when loss experience is limited or immature.

How is AI used in treaty pricing?

AI agents automate the most time-consuming parts of treaty pricing: extracting and cleansing historical loss data from bordereaux and loss runs, populating burning cost templates from structured and unstructured data sources, flagging data quality issues and IBNER patterns, running sensitivity analyses across attachment points and rate-on-line assumptions, and generating pricing memos with full audit trails. This reduces pricing preparation time from days to hours.

What data is needed to price a reinsurance treaty?

To price a reinsurance treaty you need: subject premium income by year (minimum 5 years, ideally 10), historical loss data paid and incurred with large loss detail, exposure data including sums insured distribution and geographic breakdown, development triangles for long-tail classes, and current portfolio structure. AI agents can extract all of this from cedent-provided documents automatically.

What is rate on line in excess of loss reinsurance?

Rate on line (ROL) is the reinsurance premium expressed as a percentage of the reinsurance limit. For example, an XoL layer of $10M xs $10M priced at $500,000 has an ROL of 5%. The minimum rate on line (MROL) is the minimum premium charged to make a layer economically viable regardless of burning cost.

How long does treaty pricing take with AI automation?

Manual treaty pricing typically takes 2–5 days per renewal. With AI automation, data gathering, extraction, and template population complete in under 2 hours. Actuaries review and adjust the AI-generated analysis rather than building it from scratch — reducing total pricing time by 70–85% per treaty.

What is IBNER and why does it matter in treaty pricing?

IBNER (Incurred But Not Enough Reported) is the development on known claims that have been reported but not fully reserved. In long-tail classes like liability and workers' compensation, IBNER can significantly exceed IBNR. Correctly adjusting historical burning costs for IBNER is critical — understating IBNER leads to underpriced treaties. AI agents identify IBNER patterns from development triangles automatically.

What is the difference between proportional and non-proportional treaty pricing?

Proportional treaties (quota share, surplus share) are priced based on the ceding commission adequacy relative to the cedent's loss ratio and expense base. Non-proportional treaties (XoL, stop loss) are priced using burning cost or exposure rating to determine the premium for a specific layer of loss. AI tools handle both: commission adequacy analysis for proportional, burning cost and exposure rating for non-proportional.

Automate your treaty pricing pipeline

The Reinsured.AI pricing agent extracts, cleanses, and calculates — so your actuaries price more treaties in less time.