In the first half of 2026, US surplus lines stamping offices recorded 4.28 million filed items, up 16.9%, for $47.6 billion of premium, up 2.8%. Average premium per item fell 12%, from $12,628 to $11,114.
Two carriers reported into that market in late October. Kinsale says it runs over 100 AI agents and skills. Hanover credits AI-enabled intake and triage for faster E&S growth. We read both claims against the unit that now sets E&S margins: the cost of handling one piece of work.
What the stamping offices recorded
The mid-year assessment, sourced from the Wholesale & Specialty Insurance Association and the Florida Surplus Lines Service Office, covers 15 stamping office states. Item counts outpaced premium in 14 of them. Arizona is the exception.
The 3 largest states show the pattern at size. Texas filed 20.9% more items for 5.0% more premium. California filed 22.6% more for 4.0% more. Florida filed 14.4% more items while premium fell 5.6%. Premium per item fell 13% in Texas, 15% in California and 18% in Florida.
An expert objects at once, and correctly. An item is a filed transaction after binding, not a submission. The submissions behind each item are more numerous still. Mix also moves the average: property premium fell 13.7%, while residential homeowners premium, a smaller ticket, rose 20.2%.
Both points change the reading of the 12%, not its sign. Part is rate, part is mix. Either way, carriers and brokers filed more work for each premium dollar than a year earlier.
In a softening E&S market, the unit of revenue shrinks and the unit of work does not. AI earns its budget on the second one. Hikari Blue · operator note
What Kinsale and Hanover reported
Kinsale reported on October 22. Gross written premiums fell 4.8% to $462.9 million, with the Commercial Property division down 26.8%. The expense ratio rose to 22.0% from 21.0%. The release attributes the rise to lower ceding commissions on higher reinsurance retention, not to operating cost.
On the call, management said new business submissions grew 6%, and 10% excluding Commercial Property. Chief Analytics and Technology Officer Salmaan Allibhai said the company used "over 100 agents and skills to process submissions, improve underwriting, perform analytics." Chief executive Michael Kehoe expects the expense ratio to "drift downward over time, not up, mostly because of technology."
Our crude ratio puts gross written premium per new business submission down about 10% in a year. It is crude because premium includes renewals. It lands close to the market's 12% on a different unit, which is the point: 2 independent measures show about a tenth less premium per unit of work.
Hanover reported on October 28. Specialty net premiums written rose 3.3% to $391.6 million, and the consolidated expense ratio fell to 30.9% from 31.3%. On the call, chief executive Jack Roche said E&S growth accelerated from 6.5% to 11.7%, supported by "AI-enabled submission intake and triage capabilities."
Hanover discloses neither the size of its E&S book nor its submission counts. The 11.7% cannot be turned into a unit cost from outside. The third-quarter market figures are not yet published, so the gap against the market's 2.8% first-half growth is suggestive, not proof.
Where the value sits
Our reading separates 3 pools. The first is defensive. If premium per item falls 12% and handling cost per item holds, that cost rises about 14% as a share of premium. A 10-point operating expense component becomes 11.4 points with no change in staff. That is an illustration, not a carrier figure.
The second is selection. Triage decides which submissions get underwriter time. Its value shows in the loss ratio, which moves slowly: Kinsale's was 53.4% against 53.9% a year earlier.
The third is growth where pricing still hardens. Per the same mid-year data, non-professional liability premium rose 11.2% to $18.8 billion, professional liability 15% and auto liability 15.8%. Triage capacity lets a carrier take share in those lines without hiring underwriters at the pace of submissions.
The first pool is the one a CFO can bank this year. It is less exciting than a growth claim and easier to measure.
What management decides now
Report cost per submission handled and cost per bound item, by line, every quarter. The expense ratio hides both: Kinsale's rose 1 point for a reinsurance reason, and Hanover's fell 0.4 point with no unit disclosed.
Split the AI business case in 2 lines. Capacity is submissions handled per underwriter at constant quality, and it can be approved on evidence within 2 quarters. Selection is the loss ratio on triaged business, and it is monitored over accident years before anyone books it.
Point triage at the hardening casualty lines first. That is where handled volume converts into premium rather than into declines.
Keep a decline log. Every submission an agent declines or deprioritizes carries a recorded reason and a named reviewer. It is the record a broker, an auditor or a regulator asks for first.
What could prevent value capture
Reinsurance and commissions first. Kinsale's quarter shows a ceding commission change moving the expense ratio by more than any disclosed technology effect. Without a unit cost, the AI signal disappears in the ratio.
Systems second. Kehoe says Kinsale runs no legacy applications and builds its core system with its own engineers. Carriers on older policy administration systems pay integration cost before triage pays back. Hanover says its AI-enabled data exchange went from concept to production in 3 months.
Governance third. The NAIC model bulletin of December 4, 2023 expects insurers "authorized to do business in this state" to maintain a written AIS program for AI systems that make or support decisions, underwriting included, vendor systems included. It allows that program to rely on the NIST AI RMF 1.0.
Surplus lines carriers are typically non-admitted in the insured's state, and the bulletin's text addresses authorized insurers. Groups that write both admitted and E&S business decide whether they run 1 program or 2. We read the text; we make no claim about any state's application to non-admitted carriers.
The market last. The per-item decline comes partly from soft property pricing. If property hardens, premium per item rises and a triage case sized on volume alone loses its base.
If premium per submission falls another 10% next year, what must our cost per submission handled be to hold the expense ratio, and who owns that number?
Track one external number against one internal one. Externally, premium per filed item in the stamping office data, now $11,114 for the first half of 2026. The full-year 2026 report is the next read. Internally, cost per submission handled. If the first falls and the second falls faster, the AI program is doing the work.
Thesis. In a market that pays less per unit of work, AI triage earns its budget by lowering cost per submission handled, not by claiming premium growth. We do not sell agents. We engineer business capability
- Wholesale & Specialty Insurance Association and Florida Surplus Lines Service Office (2026). US Surplus Lines Stamping Office Mid-Year Assessment, June 30, 2026, published by SLIP. Primary source for: premium and item totals and changes for the 15 stamping office states and for each state, 2026 against 2025. slipplus.com, mid-year assessment
- Business Insurance (August 4, 2026). Surplus lines premium growth slows sharply in first half of 2026. Press report of the WSIA mid-year data. Source for: property premium down 13.7%; non-professional liability up 11.2% to $18.8 billion; professional liability up 15%; auto liability up 15.8%; residential homeowners up 20.2%. businessinsurance.com
- Kinsale Capital Group, Inc. (October 22, 2026). Form 8‑K, Exhibit 99.1, third quarter 2026 results. Primary source for: gross written premiums of $462.9 million, down 4.8%; Commercial Property division down 26.8%; expense ratio of 22.0% against 21.0% and its attribution to lower ceding commissions; loss ratio of 53.4% against 53.9%. sec.gov, Exhibit 99.1
- TradingKey (October 2026). Kinsale Capital Group third quarter 2026 earnings call transcript. Third-party transcript, not issued by the company. Source for: new business submissions up 6%, 10% excluding Commercial Property; "over 100 agents and skills"; expense ratio expected to "drift downward over time"; no legacy software applications. tradingkey.com, call transcript
- Kinsale Capital Group, Inc. (April 29, 2026). Form 8‑K exhibit, press release on the realignment of analytics and technology groups. Source for: Salmaan Allibhai, Executive Vice President, Chief Analytics and Technology Officer. sec.gov, press release
- The Hanover Insurance Group, Inc. (October 28, 2026). Form 8‑K, Exhibit 99.1, third quarter 2026 results. Primary source for: Specialty net premiums written of $391.6 million, up 3.3%; consolidated expense ratio of 30.9% against 31.3%. sec.gov, Exhibit 99.1
- Investing.com (October 2026). Earnings call transcript, The Hanover Insurance Group, third quarter 2026. Third-party transcript, not issued by the company. Source for: E&S growth from 6.5% to 11.7% and "AI-enabled submission intake and triage capabilities"; data exchange "from concept to production in just 3 months." investing.com, call transcript
- National Association of Insurance Commissioners (adopted December 4, 2023). Model Bulletin: Use of Artificial Intelligence Systems by Insurers, AIS Program section and paragraphs 1.5, 1.6 and 1.8. content.naic.org, model bulletin
- National Institute of Standards and Technology (January 2023). Artificial Intelligence Risk Management Framework (AI RMF 1.0), NIST AI 100‑1. nvlpubs.nist.gov, NIST AI 100‑1
- Our arithmetic, on reported inputs. Premium per item, 15 states: $47,583,194,507 / 4,281,444 = $11,114; $46,267,052,597 / 3,663,960 = $12,628; change −12.0%. Texas: $11,359 against $13,077, −13.1%. California: $11,818 against $13,926, −15.1%. Florida: $7,638 against $9,263, −17.5%. Kinsale: 0.952 / 1.06 = 0.898, about −10% gross written premium per new business submission; crude, since premium includes renewals. Cost share: 1 / 0.88 = 1.136, about +14%; 10 points × 1.136 = 11.4 points, an illustration.
The Hikari Blue team · Austin, November 2026