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A person who wishes to rely on certain facts in a court hearing generally has a duty to adduce sufficient evidence of those facts. This 'evidential burden' is also sometimes referred to as an 'evidential burden of proof', but this term is misleading. A party to a court hearing that has aburden of proof has a duty not only to adduce evidence of the facts that support its argument, but to prove those facts to the requisite standard (see standard of proof). The distinction between an evidential burden and a burden of proof is important in a number of defences to criminal charges, such as Self defence. To plead self-defence, the defendant much adduce some admissible evidence that he actually was acting in self-defence, but he does not have the duty of proving it. The prosecution retains a duty to prove that the defendant's assertion of self-defence is ill-founded, and prove it beyond reasonable doubt. For cases where there may be a true burden of proof on the defendant, see reverse burden of proof.

Whether the evidential burden has been discharged is a question of law, not a question of fact. This means that in a jury trial it is for the judge to determine whether the evidential burden has been satisfied, before the question whether the full burden of proof has been discharged is put to the jury. If the prosecution has not satisfied the evidential burden, the judge may refuse to allow the jury to consider the evidence. If this leaves no evidence for the prosecution, then by definition there is 'no case to answer', and the judge may withdraw the case from the jury (see: Direction to acquit). Note that the CJA_2003 now gives the prosecution a right of appeal against directions to acquit.