Mistake is a term of art in both contract law and criminal law in England and Wales.
Contents
Contract law
Mistakes are a group of rules in English contract law, which happen to share the same name. If the law deems a mistake to be sufficiently grave, then a contract entered into on the grounds of the mistake may be void. A mistake is an incorrect understanding by one or more parties to a contract. There are essentially three types of mistakes in contract,
Common mistake
Res Sua, there is a mistake as to the title/name of an involved party (where the subject matter already belongs to oneself for example)
Res Extincta, where subject matter does not exist
Mutual mistake
Unilateral mistake to identity
Mistake as to identity occurs when one party – usually fraudulently – believes themselves to be bargaining with another, uninvolved, third party. In a typical situation of this kind, the contract will either be void for mistake, or voidable for fraud. Such a distinction depends on the manner in which the contract was made.
In the leading case of Cundy v Lindsay, Lindsay & Co sold handkerchiefs to a rogue pretending to be an existent and reputable firm Blenkiron & Co (they were dealing by correspondence). The contract was held to be void for mistake because Lindsay & Co had intended to contract with Blenkiron & Co, not the rogue. Lindsay & Co were able to recover the handkerchiefs from a third party who had purchased them from the rogue (as the rogue did not have good title to pass on to them).
Contrast with King's Norton Metal Co v Edridge Merrett & Co, in which a similar situation occurred except that rogue used the name of a non-existent company. The seller could not claim they had intended to contract with the non-existent company, so the contract was merely voidable for fraud, and the third party obtained good title to the goods.
Contrast also with Phillips v Brooks. There the contract was made face to face. The court presumed that the seller intended to contract with the person in front of them, so the contract was not void for mistake to identity.
Although Cundy v Lindsay and Phillips v Brooks have had a difficult co-existence which has led to confusion (e.g. Ingram v Little,) the principle was upheld by a 3:2 majority in the House of Lords decision of Shogun Finance Ltd v Hudson. The minority of Lord Nicholls and Lord Millett argued strongly for the abandonment of Cundy v Lindsay and in favour of the principle that all mistakes for identity merely render a contract voidable; for instance, Lord Nicholls argued that the loss should be borne by the seller, "who takes the risks inherent in parting with his goods without receiving payment", rather than by the innocent third party.
Unilateral mistake as to terms
Non Est Factum
Rectification
Mistake of fact
Mistake of fact may be a defence in criminal law if is genuine, whether or not it is reasonable.
In DPP v Morgan an RAF officer told three other officers to have sex with his wife, and that she would pretend to refuse just to be stimulating. They pleaded mistake, and the jury did not believe them. The House of Lords held that the judge had wrongly directed the jury that the mistake must be a reasonable one; the correct legal test was whether the defendants had honestly believed the wife was consenting, not whether they reasonably believed this. However, on the facts the House of Lords held the conviction was nonetheless safe despite the misdirection. R v Williams (Gladstone) confirmed the principle stated in Morgan that a belief that a certain set of facts are true does not need to be reasonable to operate under the defence of mistake. It merely needs to be genuine. However, the reasonableness of that belief is material in the jury deciding whether the defendant had actually held that belief.
An exception to this appears to be bigamy (see R v Tolson (1889) 23 QBD 168).
The Sexual Offences Act 2003 has introduced a hybrid test of reasonable belief as to consent. The defendant must now be seen to have taken steps to ascertain clearly whether the "victim" was consenting in all the circumstances. This abolishes the defence of a genuine though unreasonably mistaken belief as to the consent.
Mistakes about the criminal law
It is not a defence that the defendant held an honest and reasonable belief that what he was doing was not criminal. Where the defendant is a foreigner, and the offence is not criminal in his own country, the fact of such a belief is still not a defence. It is not a defence that the defendant believed that he would not be prosecuted for what he was doing.
Offences created by statutory instruments
Section 3(2) of the Statutory Instruments Act 1946 provides:
In any proceedings against any person for an offence consisting of a contravention of any such statutory instrument, it shall be a defence to prove that the instrument had not been issued by [or under the authority of] His Majesty’s Stationery Office at the date of the alleged contravention unless it is proved that at that date reasonable steps had been taken for the purpose of bringing the purport of the instrument to the notice of the public, or of persons likely to be affected by it, or of the person charged.
(Words in brackets inserted by section 1(1)(a) of the Statutory Instruments (Production and Sale) Act 1996, as read with section 1(2))
Mistakes about the civil law
A mistake about the civil law may have the effect of negativing the mens rea for an offence. See: