English law governed acquisition agreements commonly require the purchaser to notify the seller of any claim against the target - for example by a tax authority - which could give rise to a claim by the purchaser against the seller - for example under a tax indemnity ("Issue Notification"). 

It is also common that the purchaser is barred from making a claim against the seller unless notice of that claim has been given to the seller within a specified time limit ("Claim Notification"). 

In Stobart Group, the latest in a line of recent cases in the English courts on notice provisions, the Court of Appeal drew a clear distinction between these two types of clauses. 

The notice in question referred to a potential tax liability of the target and enclosed an estimate thereof. It also referred to a potential claim under the tax indemnity, but no estimate of the amount claimed from the sellers was given. The notice mentioned the Issue Notification clause, but not the Claim Notification clause. 

So, the Court of Appeal decided that the notice was only an Issue Notification, and not a Claim Notification. Therefore, the purchaser's indemnity claim was time-barred under the Claim Notification clause.  

A Claim Notification must "make clear in sufficiently formal terms that a claim is being made against the vendors". Notice of the possibility of a claim is insufficient. It is important to comply strictly with the terms of the notice provision and advisable to make express reference to the Claim Notification clause, to use the defined term for claims against the seller and to include an estimate of the amount to be claimed from the seller.