A voidable contract is a formal agreement between two parties that might be rendered unenforceable for various legitimate reasons. A voidable contract is a legitimate contract which might be either affirmed or rejected at the option of one of the parties. At most, one party to the agreement is bound. Reasons that can make an agreement voidable include coercion, undue impact, distortion or misrepresentation.

In contract law, a mix-up is an incorrect conviction, at contracting, that specific facts are valid. It can be argued as a defense, and if raised effectively can lead to the agreement in question being discovered voidable. Common law has distinguished three types of mistake in contract: the 'unilateral mistake ', the 'mutual mistake ' and the 'common mistake '. The distinction between the 'common mistake ' and the 'mutual mistake ' is vital.

In an agreement setting, a mistake is an error in the meaning of words, laws, or facts which causes one or both parties to enter into the contract without fully understanding the outcomes or obligations suggested by the agreement.
Unilateral mistakes

A “unilateral mistake” is such a blunder, to the point that is held by only one party and not shared by the other party. Besides, a unilateral mistake happens when only party is mistaken as to the subject matter or the terms contained in the contract agreement. This type of mistake is for the most part more common than other types of contract mistakes, such as a mutual mistake