After a decade of limited case law, business interruption insurance has become one of the most heavily litigated and closely scrutinized areas of the insurance market. Although many headline disputes have now been resolved, several important issues continue to divide insurers and policyholders.

In practice, these disputes are less often about whether a policy responds at all than about the mechanics of indemnity: the proper construction of the wording, the operation of trends clauses and the quantification of loss.

For corporate policyholders, the consequence is clear. Maximising recovery requires both close attention to the policy wording and a strategic approach to the presentation and advancement of the claim.

Causation and the Proper Scope of Cover

Causation remains central to many business interruption disputes. Insurers frequently seek to attribute losses to a range of competing factors, only some of which fall within the scope of cover.

From the policyholder’s perspective, that approach may produce an unduly narrow assessment of indemnity, particularly where insurers isolate a single proximate cause and downplay the broader factual matrix in which the loss arose.

The courts have repeatedly emphasised that causation in insurance law is not always a simple “but for” exercise. Where multiple interrelated causes operate in combination, the task is to assess whether the insured peril forms an effective cause of the loss, rather than the sole or dominant one.

In practical terms, policyholders should be cautious about accepting attempts to disaggregate losses artificially. If the insured peril forms part of an indivisible chain of causation, there may be strong grounds to resist a reduction in the claim.

Trends Clauses and the Adjustment of Loss

If causation determines whether a claim is covered, trends clauses often determine how much is recoverable.

These provisions adjust the indemnity to reflect what the business would have earned “but for” the insured event. In theory, they produce a fair and realistic counterfactual. In practice, they are often the focal point of disagreement.

Insurers commonly rely on trends clauses to remove elements of loss said to be attributable to wider market conditions or pre-existing business issues. That may be appropriate in some cases, but difficulties arise where those conditions are themselves closely linked to the insured peril.

The tension is obvious. The indemnity should not put the insured in a better position than it would have occupied absent the loss, but nor should the clause be used to deprive the policyholder of the cover it purchased.

For policyholders, the key is to scrutinise carefully the assumptions underlying any proposed adjustment. In particular:

• Are the insurer’s counterfactual assumptions realistic and evidence-based?
• Do they improperly exclude loss which is, in substance, connected to the insured peril?
• Do they reflect the wording of the clause, rather than a generalised view of fairness?

Because these questions are highly fact-sensitive, early engagement with forensic accountants can be critical in framing the debate.

Aggregation and the Application of Policy Limits

Another recurring issue is whether losses should be aggregated when applying limits of indemnity and deductibles.

The financial impact can be significant. A policy which responds on a “per occurrence” basis may, depending on the wording, allow multiple recoveries where losses arise from separate events. Conversely, insurers may argue for a single aggregated limit, substantially reducing the amount payable.

Everything turns on the drafting. Terms such as “occurrence”, “event” or “originating cause” are often left undefined, or defined in language which provides scope for competing interpretations.

Where a business has suffered losses across multiple sites or over an extended period, the issue becomes particularly acute. The question is not simply how many losses have been suffered, but how they should be characterised within the policy framework.

Policyholders should therefore address aggregation at an early stage, as the analysis will often influence both quantum and overall claims strategy.

The Evidential Burden and Claims Preparation

Even where issues of principle are resolved in the policyholder’s favour, the success of a business interruption claim ultimately depends on evidence.

Insurers typically require detailed financial material, including historical trading data, management accounts and projections. The methodology used to calculate loss is also likely to attract close scrutiny.

Disputes frequently arise where:

• Different methodologies produce materially different outcomes;
• Assumptions about future performance are challenged; or
• The link between the insured peril and the loss is said to be insufficiently evidenced.

In this context, the quality of preparation can be decisive. A well-structured claim, supported by coherent analysis and contemporaneous evidence, is far more likely to withstand challenge.

Conversely, a reactive or poorly evidenced approach can allow insurers to dictate the narrative of the claim from an early stage.

The Importance of Policy Wording

Underlying each of these points is the critical role of the policy wording.

Business interruption policies are not standardised, and small differences in drafting can produce materially different outcomes. That is particularly true in relation to:

• The scope of the insuring clause;
• The operation of extensions and sub-limits;
• The wording of trends and aggregation provisions; and
• The definitions which underpin the policy as a whole.

For corporate policyholders, the lesson is clear. Issues that later give rise to claims disputes can often be addressed, or at least mitigated, at placement or renewal.

A careful review of wording, informed by recent disputes and market developments, can significantly reduce the scope for uncertainty later on.

Concluding Remarks

Business interruption claims are rarely straightforward. Although the broad principles of coverage may be well understood, the detail continues to generate complex and often high-value disputes.

For policyholders, the focus should be on maintaining control from the outset: understanding the policy, presenting the claim clearly and engaging robustly with insurer positions where necessary.

In an environment where outcomes frequently turn on fine distinctions of wording and evidence, a disciplined and strategic approach remains the best means of securing a full and proper recovery.

If you have any questions please contact a member of Edwin Coe’s Insurance Disputes team.

Please note that this blog is provided for general information only. It is not intended to amount to advice on which you should rely. You must obtain professional or specialist advice before taking, or refraining from, any action on the basis of the content of this blog. Please also see a copy of our terms of use here in respect of our website which apply also to all of our blogs.