contracts

capacity

Capacity is the legal ability of a person to enter into a binding contract. A party with capacity must be of legal age and mentally competent to understand the nature and consequences of the agreement. Minors, people adjudged mentally incompetent, and in some cases people who are severely intoxicated lack full capacity. Contracts signed by those lacking capacity may be void or voidable depending on the situation and state law.

Exam tip
Capacity is one of the essential elements of a valid contract (with offer and acceptance, consideration, and legal purpose). Lack of capacity due to age usually makes a contract voidable.
Example
A court-appointed guardian signs a sale contract for an elderly owner who has been declared incompetent, since the owner lacks capacity to sign herself.

Related terms & state variants

Sources

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Last verified: 2026-10-23