Defects of Consent: One Ground at a Time

Mistake: the party who could have checked

Facts of the case

• the assumption is that of the party in relation to the contract
• the assumption is erroneous and relates to facts or to law existing when the contract was concluded
• the mistake was of such importance that a reasonable person in the same situation would only have concluded the contract on materially different terms or would not have concluded it at all
• the other party made the same mistake, or caused it, or knew or ought to have known of it
• it was contrary to reasonable commercial standards of fair dealing to leave the mistaken party in error

• is-mistake: Established
• may-avoid-for-mistake: Established