A company operates 20 facilities. No location accounts for an excessive share of production. Revenue is spread across customers and regions. From a traditional concentration perspective, the business looks reasonably diversified. Then an insurer maps the supply chain: six plants depend on components ultimately produced at the same facility, several Tier 1 suppliers buy from the same Tier 2 manufacturer, and a material assumed to be multisourced actually comes from one geographic cluster. The concentration was there all along. It just wasn't visible from the company's own footprint, and that distinction is becoming more important in insurance underwriting as supply-chain mapping moves beyond lists of direct suppliers.
Marsh recently described a global semiconductor manufacturer that entered its property damage and business interruption renewal with incomplete data on 84 named supplier sites and little insight into the thousands of Tier 2 and Tier 3 suppliers sitting further upstream. Supply-chain analysis ultimately validated 94 supplier sites and uncovered more than 16,000 Tier 2 and Tier 3 suppliers, identifying structural risks including bottlenecks and concentrations that the company used to update its supplier schedule and support contingent business interruption coverage tailored to its actual exposure. The implication extends well beyond semiconductors: supplier concentration is becoming measurable enough to influence how insurers understand a company's risk in the first place.
Five Suppliers Can Still Represent One Exposure
Procurement has traditionally measured concentration using direct relationships: how much the company spends with its largest supplier, what percentage of a critical component comes from one vendor, whether there is an approved second source. Those measures remain useful, but they can miss common dependencies farther upstream. Two competing suppliers can purchase the same chemical from one producer. Multiple electronics manufacturers can rely on one semiconductor fabrication process. Several pharmaceutical manufacturers can source an active ingredient or key starting material from the same facility or geographic region. On a procurement spreadsheet, those relationships look diversified. From an interruption perspective, they may represent one risk.
Marsh says modern supply-chain mapping increasingly looks beyond Tier 1 suppliers specifically to uncover shared sub-suppliers, critical sites, bottlenecks and geographic concentrations that can create single points of failure, information that can then be incorporated into insurance submissions and used to support discussions about property and CBI limits. That creates a new problem for companies that have treated supplier diversification primarily as a purchasing exercise: adding vendors does not necessarily diversify the underlying exposure, a gap that echoes how procurement teams are already learning that redundancy on paper and redundancy in practice are not the same thing.
Business Interruption Is Moving Beyond the Company's Property Line
The insurance consequences are easiest to see in business interruption. Traditional business interruption insurance generally responds when covered physical damage to a company's own property interrupts operations. Contingent business interruption extends that concept to dependent properties, including critical suppliers and customers, because the event that shuts down production may occur hundreds or thousands of miles from the insured company's facilities. Hannover Re notes that BI and CBI losses typically account for 50% to 70% of catastrophe losses, and identifies supply-chain transparency as a major underwriting problem, particularly because insurers need to understand interdependencies among first-, second- and third-tier suppliers and their potential accumulation exposure. The insurer is therefore not simply interested in whether a company has suppliers. It needs to understand what happens when one of them disappears, and increasingly, whether several apparently independent suppliers could disappear at the same time.
The Risk Environment Is Making That Question More Important
The underwriting interest is arriving as supplier financial risk itself is increasing. Allianz Trade now forecasts global business insolvencies will rise another 6% in 2026, making this the fifth consecutive year of increases, and expects U.S. insolvencies to rise 9% this year. Its 2026 global survey found an equally important shift in what companies themselves fear: supply-related risks, including supplier bankruptcies and input shortages, jumped to the second-largest concern among surveyed companies, cited by 57%, up 30 percentage points, while supply-chain complexity and concentration was cited by 45%. Meanwhile, Allianz Commercial's 2026 Risk Barometer ranks business interruption, including supply-chain disruption, as the world's third-largest corporate risk, and only 3% of respondents described their supply chains as "very resilient." Companies are becoming more dependent on interconnected supplier networks at the same time insolvency, geopolitical and trade risks are making disruptions more plausible.
Better Supply-Chain Data Can Affect the Insurance Outcome
Greater transparency does not automatically mean a higher premium. The Marsh semiconductor case demonstrates why. Better data allowed the manufacturer and insurer to distinguish actual concentrations from assumed ones and align CBI coverage with the company's real supplier exposure, producing coverage genuinely matched to its risk rather than a generic estimate. That changes the incentive around supply-chain transparency. Companies have historically had reasons to map suppliers for procurement continuity, regulatory compliance or ESG due diligence. Insurance creates another: a business that can demonstrate geographic diversification, qualified alternative sources, credible continuity plans and visibility into Tier 2 and Tier 3 dependencies may present a different risk than one that simply tells an underwriter it has several suppliers, a distinction that mirrors how traditional risk models are being forced to account for interdependencies they were never built to capture. The number of suppliers matters less if they all depend on the same place.
Finance Needs the Same Supplier Map as Procurement
That makes supplier concentration a cross-functional financial issue. Procurement knows which vendors provide critical components. Operations knows how quickly inventory would run out. Risk management understands the insurance program. Finance knows the revenue and cash-flow consequences of an extended shutdown, and those views increasingly need to be combined, a coordination gap already visible in how lenders and insurers are integrating supply-chain concentration alongside physical climate exposure and infrastructure reliability into underwriting decisions. The questions are straightforward but difficult to answer: which suppliers could stop a facility, how much revenue depends on them, which apparently independent suppliers share upstream sources, how long would replacement take, which locations are represented on the CBI schedule, and do the limits reflect the actual financial consequence of losing them?
The insurance renewal can expose gaps in those answers. A company may believe it diversified a critical component because procurement added a second supplier. An insurer looking several tiers deeper may discover something different: the two suppliers lead back to the same factory. At that point, supplier concentration is no longer only a procurement risk. It is an insurable financial exposure.
