When a professional firm identifies a systemic issue - a flawed calculation method used across many projects, a defective standard document, a recurring advice error - it faces a choice. It can notify each affected matter specifically, or it can make a single blanket notification (sometimes called a block or hornet's nest notification) intended to sweep up all claims that may flow from the underlying problem. Both are recognised, but they carry different risks, and the case law is unforgiving of blanket notifications that lack substance.
The validity of a blanket notification was central to HLB Kidsons v Lloyd's Underwriters [2008] EWCA Civ 1206. The Court of Appeal held that for a notification to be effective it must convey to the insurer, with sufficient particularity, the circumstances relied upon. A notification cannot be so general or so lacking in detail that the insurer cannot identify what has been notified. A firm cannot simply write to its insurer saying, in effect, that something somewhere may have gone wrong and expect every future claim to be caught. The notification must have enough content for the insurer to understand the nature of the matter and its potential scope.
Kajima UK Engineering v Underwriter Insurance Co [2008] EWHC 83 (TCC) illustrates the other edge of the same rule. There the court examined whether later claims fell within the scope of what had actually been notified. The lesson is that a notification is only as wide as its content: claims arising from matters not fairly described in the notification may fall outside it. A blanket notification framed around one defect will not necessarily capture a different defect that the firm knew about but did not describe.
For design and built-environment professionals the choice is common. An engineering practice that discovers a flawed load assumption used on multiple schemes, or an architecture firm that finds a specification error repeated across projects, must decide whether to notify each project or make a considered block notification of the underlying error and its known consequences. Our guides to architects' PI insurance and engineers' PI insurance explain how these firms carry aggregated exposure that a well-framed notification can address.
A good blanket notification identifies the root cause, the population of matters potentially affected, the mechanism by which claims might arise and the firm's current knowledge of quantum. It is specific enough to be valid yet wide enough to capture the field of foreseeable claims. Drafting it is a skilled exercise, because too little detail risks invalidity while over-reaching can prompt an insurer to load or restrict the next renewal. Apex works with firms to frame notifications that meet the specificity the courts require while protecting the position across a book of affected work.
Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Firm reference number 724952. This entry is general information, not advice on any particular policy.