In England and Wales, there is a three-year limitation period in most personal injury actions. In some HCA cases, and in professional negligence cases, it is six years. This is the period during which the claim must be brought. It begins in theory when the cause of action (i.e. the index incident) occurred. In HCA and clinical negligence cases, it begins when the claimant has the relevant ‘knowledge’: (1) that the injury was significant (whether a reasonable person with the claimant’s knowledge would have considered the injury sufficiently serious to justify suing a defendant who did not deny liability and had the means to pay, an objective test for which the impact of the claimant’s injuries on his ability to issue proceedings is not a relevant consideration (A v. Hoare [2008] UKHL 6); (2) that the injury is attributable in whole or part to the act or omission which constitutes the alleged negligence or breach of duty; and (3) the identity of the defendant.