Contingent Business Interruption: When a Supplier’s Loss Becomes Yours

Key takeaways

• Standard business interruption covers lost income when your own property is damaged. Contingent business interruption (CBI) addresses income lost when a supplier’s or customer’s property is damaged and it stops you.
• A single-source supplier is the classic CBI exposure: one fire or flood at their site can idle your line.
• CBI often requires the supplier to be named or scheduled, and triggers, limits, and waiting periods vary widely.
• Mapping your critical suppliers is the work that makes the coverage meaningful.

What is the difference between business interruption and contingent business interruption?

Business interruption (BI) coverage replaces income you lose when your own property suffers a covered loss, like a fire that shuts your shop. Contingent business interruption (CBI) extends that idea outward: it can respond when income is lost because a business you depend on, usually a supplier or a major customer, suffers a covered loss at their location.

The distinction matters because operations rarely fail in isolation. A week-long warehouse fire in Los Angeles in 2026 reportedly disrupted nearby businesses and air quality, a reminder that a loss two doors down, or two states away, can land on you even when your own building never burns.

How does a single-source supplier become a single point of failure?

Picture the one supplier who makes the only resin grade your molding line is qualified to run, or the only shop that grinds your specialty tooling, or the one vendor a distributor depends on for a top-selling line. Reliable, good price, leaned on for years. Then their building floods. They are down for months. You are down with them, because you never qualified a second source.

That is the single-source trap. It is efficient right up until the day it is not, and it is exactly what CBI is built to address. The catch is that CBI is neither automatic nor unlimited.

What does contingent business interruption actually require?

A few features show up again and again, and each is worth checking:

• Named or scheduled suppliers. Some CBI only responds for suppliers you have specifically listed. An unlisted supplier may trigger nothing.
• A covered cause of loss. The supplier’s shutdown usually has to come from a peril your policy covers. A supplier failing for financial reasons, or a pure logistics snarl, may not qualify.
• Waiting periods and limits. Like standard BI, CBI often has a time deductible before it pays and a cap on what it pays.
• Tiers of dependency. Coverage may treat your direct suppliers differently from your suppliers’ suppliers, and the deeper tiers are harder to cover.

Because these terms vary so much, two policies that both say “contingent business interruption” can behave very differently when a real loss hits.

This is general information rather than a coverage determination. Read your actual policy, including endorsements and exclusions, to see how its CBI terms, triggers, and limits apply to you.

What should I do first?

Map your dependencies before you shop coverage. List the suppliers and customers you genuinely cannot operate without, mark which are single-source, and note how long you could run if each disappeared. That map does two jobs: it tells your agent which suppliers may need to be named, and it shows you where a backup source or a safety-stock buffer would cut your risk regardless of insurance.

Supplier risk is increasingly a cyber issue too, since a supplier knocked offline by ransomware can idle you just like a fire would, which we cover in supply-chain and vendor cyber risk. It is also a natural item for your mid-year insurance review.

FAQ

Does my regular policy already include CBI? Sometimes a limited amount is built in, but it may be small or restricted to named suppliers. Check the specific terms rather than assuming.

What if my supplier goes down from a cyber attack, not a fire? That depends on your policy’s covered causes of loss. Cyber-driven outages may fall under different coverage, which is worth confirming.

Can I cover my suppliers’ suppliers? Deeper tiers are harder and not always available. Secure your direct critical suppliers first.

Map it, then cover it

If you have a supplier you cannot replace overnight, that is the place to start. When you want to look at how your program handles supplier-driven downtime, you can request a quote here.