Mistake and innocent misrepresentation are two concepts that are closely linked together, of course one is more innocuous sounding than the other. Sometimes the lines blur and commentators are in disagreement about what a mistake is. The classification thus bleeds into many vague territories. Usually the working definition of mistake is that parties who although on appearances are in agreement, have jointly entered into contracting upon a false but fundamental assumption. Notice the similarity with wholly innocent misrepresentation, where the person who misrepresents may have reasonable grounds for believing in the truth of his assumptions that leads to the misrepresentation he makes. Notice here that both parties are reliant on an assumption that they will later find turn out to be false.
Innocent misrepresentation is hinged on representations made that induce a party into a contract, as well as the honest belief of the representor that would signal his culpability or lack thereof in the case matter. As for mistake it is split up into many different and at times contentious categories from common to mutual, as well as unilateral whose existence is doubted by some, as well as to identity and documents. Sometimes the distinction between a void contract and a voidable contract also becomes a significant issue especially when a third party enters the issue.
In mistake cases the contract would be made void and usually for innocent misrepresentation the remedy to follow would be rescission, specific performance will be refused in both cases (except under occasions at equity) or if there was some form of affirmation in the knowledge. No damages can be claimed under either. Although it is possible to have a case under both different legal concepts. That is one may be able to bring about a mistake claim as well as a misrepresentation claim concurrently and choose the more solid of the two. But keep in mind that should there be double recovery it is unlikely to be granted for misrepresentation inducements.