A business can have healthy sales, a respectable accounting gross profit and still be seriously underinsured when trading stops. The problem often begins with two words that appear familiar: gross profit. In UK business interruption insurance, they can mean something quite different from the figure shown in annual accounts.
Why business interruption gross profit differs from accounting profit
In accounts, gross profit is generally sales less cost of sales. What sits within cost of sales depends on the business and its accounting practices. Direct labour, production overheads and other expenses may be included.
Business interruption policies instead use their own defined measure of gross profit, sometimes called insurable gross profit. A common UK approach starts with turnover, adjusts for opening and closing stock and work in progress where relevant, and deducts specified uninsured working expenses.
These uninsured expenses are identified by the policy or schedule. They are usually costs that would fall away with reduced activity, such as certain purchases or outward carriage. The exact list matters: never assume an expense is excluded merely because an accountant classifies it as a cost of sales.
How to calculate insurable gross profit
The starting point is the gross profit definition in the actual wording and schedule. For a straightforward service or trading business without material stock adjustments, the calculation can be expressed as turnover minus the uninsured working expenses specifically listed in the policy.
For businesses holding stock or work in progress, a common difference-basis formula is turnover plus closing stock and work in progress, less opening stock and work in progress and specified uninsured working expenses. Accountants should reconcile those figures to the business’s records rather than substitute an accounting gross margin.
A practical example: a UK furniture maker
Imagine a furniture manufacturer with annual turnover of £1,000,000. Its policy specifies £380,000 of materials and purchases and £40,000 of outward delivery costs as uninsured working expenses. Assuming no relevant stock movement, its business interruption gross profit would be £580,000.
Now suppose the company also includes £120,000 of production payroll in cost of sales for accounting purposes. Its accounts might show gross profit of £460,000. But if that payroll is not an uninsured working expense under the policy, using £460,000 for insurance could omit £120,000 of the business’s annual exposure.
The indemnity period changes the amount needed
The maximum indemnity period is the longest period over which covered financial losses can be compensated after an insured event. It may need to extend beyond rebuilding: lost customers, delayed supplies and the time required to regain sales can prolong recovery.
On a conventional sum-insured basis, £580,000 of expected annual insurable gross profit would suggest £1,160,000 for a 24-month period before allowing for anticipated business growth, price changes or other adjustments. Using only one year’s figure for a two-year exposure can leave a substantial shortfall. A declaration-linked policy may use a different method, so check its wording.
How underinsurance affects a claim
Underinsurance business interruption problems are especially painful because they may only become visible after a major loss. Some sum-insured policies contain an average clause, which reduces an otherwise covered claim proportionately when the insured amount is below the amount that should have been insured.
For example, if the required amount was £1,200,000 but the policy insured only £900,000, the business would have insured 75% of its exposure. Under a straightforward average clause, an otherwise eligible £200,000 loss might be reduced to £150,000, before other policy conditions and deductions.
Not every wording applies average in that way. Claims also depend on the insured cause, exclusions, limits, the measured reduction in turnover and any permissible increased cost of working. The Financial Conduct Authority emphasises that the policy’s definitions and basis of settlement determine the calculation.
Does a declaration-linked basis prevent underinsurance?
A declaration linked basis commonly involves estimating gross profit at the start of the period of insurance and declaring actual results afterwards, with a premium adjustment where applicable. Many wordings provide a margin above the declared amount and do not apply the traditional average clause in the same way.
That flexibility should not be mistaken for unlimited cover. Policies can cap payment, often by reference to a percentage of the declaration, and can impose conditions where declarations are significantly understated. The allowance, reporting requirements and treatment of indemnity periods longer than 12 months differ between wordings.
For a growing business, the useful question is not simply whether its cover is declaration-linked. It is whether the starting declaration uses the correct insurance definition and whether the maximum payable amount would be adequate following a serious disruption.
A sensible check before renewal
Ask your accountant and broker to work from the policy schedule together. Confirm which purchases, wages and variable charges are uninsured, account for stock movements where relevant, forecast turnover over the insured exposure and test the chosen indemnity period against a realistic recovery scenario.
Keep a written reconciliation between accounting gross profit and the insured figure. If the business acquires a new customer, expands premises or changes its supply model, review the estimate rather than waiting automatically for the next renewal. Understanding business interruption insurance cover is as much about the recovery timeline as the annual figure.
Frequently asked questions
Is business interruption gross profit the same as net profit?
No. Insured gross profit commonly includes amounts needed for continuing overheads as well as profit, whereas net profit is calculated after wider business expenses. Follow the policy’s definition rather than treating either accounting figure as interchangeable.
Which expenses are excluded from insurable gross profit?
Only the uninsured or specified working expenses identified by the policy wording and schedule should be deducted when calculating the declared figure. Typical examples can include particular purchases and delivery charges, but definitions vary.
Does declaration-linked insurance remove the risk of a reduced payout?
No. It may reduce exposure to a conventional average clause, but limits and declaration conditions still matter. An inaccurate estimate or an unexpectedly long recovery can leave a business with a funding gap.
Who should calculate the business interruption sum insured?
The business should involve someone who understands its accounts, alongside a broker familiar with the specific insurance wording. An accountant can reconcile the financial data, while the broker can clarify the required basis and indemnity period.
Making the insured figure work for your business
The most useful test is simple: if a fire stopped trading tomorrow, would the policy’s defined gross profit and recovery period reflect the money the business would actually need? Calculating from the right definition, checking the declared amount and reviewing the recovery timeline can prevent an accounting shortcut from becoming an expensive insurance gap.