Manufacturer Inland Marine: Pricing Methodology

What rating basis does Inland Marine use for Manufacturers?

The pricing unit for Inland Marine on Manufacturers is per $100 of equipment value. Carriers multiply a per-unit rate (the base loss cost set by AAIS / ISO, modified by carrier-specific factors) by the exposure to produce the base premium.

This is the most important number on the policy — it controls how renewal premiums move as your operation grows or contracts. The audit at policy expiration trues up the actual exposure against the estimated exposure used at binding, producing return premium or additional premium.

The class-code decision for Manufacturers on Inland Marine

The AAIS / ISO class assignment for Manufacturers on Inland Marine is a judgment call by the underwriter, guided by class manuals and standard operating definitions. The manufacturer provides the operational facts; the underwriter maps those facts to a class.

The wrong class is the most common cause of overpayment on Inland Marine accounts. We recommend asking the broker to confirm the assigned class code on every binder and comparing it against prior years — inconsistencies often point to a correction opportunity.

The audit basis on Manufacturers Inland Marine

Inland Marine policies on Manufacturers are typically audited at expiration. The auditor reviews actual exposure data for the policy period — payroll, revenue, vehicles, locations — and trues up the premium against what was estimated at binding.

If actual exposure exceeds estimated, you owe additional premium ("audit premium"). If actual exposure was lower, the carrier refunds the difference ("return premium"). Audit results that significantly diverge from the original estimate often trigger underwriting questions at the next renewal.

How does schedule rating affect Manufacturers Inland Marine?

Filed schedule-rating plans give underwriters discretion to apply credits or debits to Manufacturers Inland Marine based on operational qualities. The underwriter documents the rationale; the credit or debit applies through the policy term.

Schedule credits add up to real money. A 10% schedule credit on a $15,000 premium is $1,500/year — and that credit usually carries forward at renewal as long as the operational factors that justified it remain.

How three years of claims affect Manufacturers Inland Marine pricing

Manufacturers experience modifiers reflect actual loss performance against expected. The actual is your paid losses (excluding incurred-but-not-paid reserves on open claims); the expected is the class's average loss-cost benchmark.

Improving the mod is a long game. A single clean year reduces the most recent (heaviest-weighted) year's impact. Three consecutive clean years can move a debit mod into credit territory. The patience pays — mod credits compound across multiple policy lines.

State filings and Manufacturers Inland Marine renewal math

Carriers file Inland Marine rates with state insurance departments before charging them. States approve rates at varying speeds — some prior-approval states take 60-180 days, others use file-and-use frameworks that allow rates to take effect quickly.

For Manufacturers, this matters at renewal. If your state recently approved a base-rate increase for the class, that increase shows up in your renewal regardless of your individual loss experience. Tracking pending rate filings in your state can predict 6-12 months of premium movement.

Why two carriers price the same Manufacturers risk differently on Inland Marine

Two carriers can quote the same manufacturer on Inland Marine and produce premiums that differ 15-30%. The difference comes from carrier-specific loss-cost multipliers (each carrier's adjustment to the AAIS / ISO base rate), schedule-rating philosophy, and target loss ratios for the segment.

Some carriers actively pursue manufacturer business and price aggressively for it; others see the segment as marginal and price defensively. Knowing which carriers are currently in either bucket is the broker's job — and it materially affects which markets to target.