Ask companies worldwide what worries them most and the answer has been consistent for years: not being able to trade. Business interruption ranks above market volatility, political risk and natural catastrophe, because everything else eventually shows up as an interruption, and an interruption is what stops income while costs continue.
Annual corporate risk surveys place it at the top repeatedly, and note that the triggers have broadened well beyond physical damage into cyber incidents, supply chain failures, strikes and unrest.
The trigger has moved from fire to everything else
Interruption used to mean a building burned down. It now means a supplier cannot deliver, a system is encrypted, a road is blocked, or a network is down. A business insured only against physical damage is insured against the least likely cause, which is the single most common gap in small business cover.
Interconnection multiplies the damage
The more tightly a business is connected to suppliers, customers and systems, the further an incident travels. One supplier’s failure can stop your production and then your customer’s. That is why knowing your critical dependencies, the single supplier, the one system, the one person, matters more than the general resilience of your industry.
Work out how long you could survive not trading
The practical exercise is straightforward and most owners have never done it. If you could not trade from tomorrow, how long before you could not pay staff or rent? That number determines everything else: how much cover you need, how large a reserve, and how urgently you need a second supplier.
Cyber incidents are now an interruption risk, not just a data risk
An attack that locks a business out of its own systems stops trading immediately, which makes it an operational risk rather than only a compliance one. Cover, backups you have actually tested restoring, and access controls all belong in the same plan, and any breach involving personal information also triggers reporting duties.
Check what your policy actually covers
Business interruption cover varies enormously in what triggers a claim, the waiting period before it pays and the maximum period covered. Many small businesses discover the limits at the worst moment. Insurers and brokers are regulated by the Financial Sector Conduct Authority, and asking a broker to explain in writing what would and would not be covered is a reasonable request.
Frequently asked questions
Why does business interruption rank as the top corporate risk?
Because every other risk eventually manifests as an inability to trade, which stops income while costs continue.
What causes interruption now?
Supplier failure, system outages, cyber incidents, unrest and blocked logistics far more often than physical damage to premises.
What is the most common gap in small business cover?
Being insured only against physical damage, which is now the least likely cause of an interruption.
What should an owner actually calculate?
How many days the business could survive without trading before it could not pay staff and rent. That number sizes the cover and the reserve.
Is a cyber attack an interruption risk?
Yes. Being locked out of your own systems stops trading immediately, which makes it operational as well as a data protection matter.
Further reading
Originally published in January 2017. Updated September 2026 to focus on business interruption as the risk that most often ends a small business, using the lead story from the original roundup.
