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Art. 09 · What the policy says · 3 min read

Underinsurance and the average clause

Most people assume that if a loss is smaller than the sum insured, it gets paid in full. For a great many commercial policies, that is not how it works.

Suppose a building would cost £1,000,000 to rebuild, but the schedule says £600,000, because the valuation is old, or the figure was a guess, or nobody updated it after the extension. You are insured for 60% of the value.

Now a fire causes £200,000 of damage. Well within the £600,000 limit. You would reasonably expect £200,000, less the excess.

What many policies pay is £120,000. The insurer applies the condition of average: because you insured 60% of the value, they pay 60% of the loss. You have effectively been your own insurer for the other 40% without knowing it, on every claim, not just the big ones.

TRUE REBUILD COST £1,000,000 SUM INSURED £600,000 = 60% insured THE LOSS £200,000 WHAT IS PAID £120,000 £80,000 shortfall £200,000 loss × (£600,000 ÷ £1,000,000) = £120,000 paid
  • Covered
  • Yours, whether you planned for it or not
Fig. 10 · The shortfall is proportional, so it appears on every claim of every size. A business can be underinsured for years, make several small claims, and never notice the deduction.

The same principle applies to contents, to stock, and, most painfully, to business interruption, where the "value" is a projected annual gross profit that businesses routinely understate.

Some policies soften this. Ask whether yours has an "average waiver" or a "day one reinstatement" basis, both of which give you a margin before average bites. If it doesn't, the only defence is an accurate sum insured.

Use it

  • Search your policy for the word "average." It will be in the general conditions. Read what it says before you need to.
  • Treat the sum insured as a live number. Extensions, refits, new plant and construction inflation all move it. Nobody will tell you it has drifted.
  • Ask about a waiver. Many insurers will waive average if you can evidence a professional valuation, which changes the value of getting one.

Want this run against your own numbers?

We put ranges, not single figures, against the risks your business actually carries.

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Explanatory content only. This article describes how insurance and risk decisions work in general terms; it is not insurance, legal, actuarial, or investment advice, and it is not a recommendation to buy, keep or cancel any cover. Every figure and diagram is illustrative, chosen to make a mechanism visible, not to describe any particular business.