This Practice Note on professional negligence claims provides practical guidance and tips for bringing a professional negligence claim. It covers immediate considerations from identifying the duty (contractual, tortious or both) and the alleged breach, the loss and remedy sought, including causation, quantum and duties to mitigate. It also considers limitation of actions, settlement ADR and enforcement, the role of insurers in a professional negligence claim, starting the claim, disclosure and evidence and cross-border considerations.