Modern negligence law, which accident claim attorneys rely on, is founded on precedent established by the deceptively straightforward Donohue v. Stevenson case from the UK in 1932, which involved lemonade with a snail in the bottle that made the drinker unwell. However, in Donohue v. Stevenson, the case law was expanded to cover those to whom manufacturers owed a "duty of care" as opposed to just a contractual liability, which in this case would be any person who actually drank the lemonade. Prior to this, similar cases were almost exclusively based on contract, and there are records of contract/negligence cases in the UK going back as far as 1348.

The victim must have been hurt as a result of the negligent conduct of the third party defendant in order for claims to succeed. Accident attorneys use a variety of definitions of negligence because there is no statutory standard in the UK. Negligence is, generally speaking, the failure to act in a way that a reasonable person would act or the act of acting in a way that a reasonable person would not act. Uncertainty in any definition leaves it open to debate as to what constitutes and does not constitute irresponsible action.