Legal incapacity has to do with not being able to care for someone or something because you cannot do so physically or mentally. This incapacity might be short-term, long-term, or something that comes and goes with time. The word incompetent is similar to incapacity, although incompetent has to do with legal matters while incapacity has to do with medical matters. Most states use "legally incapacitated" to refer to a person who cannot take care of his or her own physical safety and health. A person must be legally competent to perform legal matters such as signing a will or entering into a contract or some other binding legal agreement.


A person can be judged incompetent by their mental condition or age. Individuals who agree to a legal transaction are responsible for the contract's obligations unless determined legally incompetent. Someone who is under age 18 or 21 (based on where the legal decisions are taking place) is not under the same laws as a person over those ages. If an underage person signed a contract, he or she is not responsible if the contract is broken. This individual is protected by public policy from negotiating contracts due to inexperience.

A person is said to have mental incapacity if he or she does not understand a contract's qualities and end result. A difference must be established between a person who is mentally incompetent and a person who has been deemed incompetent by a court of law. A person declared unable to perform appropriately in court cannot make a contract with another person. This person cannot agree on a contract, because the court has decided he or she does not understand what the contract entails. A contract made by this type of person holds no value.

When a mentally incapacitated person makes a contract and no judgment has been made on his or her mental incapacity, that person can revoke the contract. The contract would then be legally void by this individual. If this person is later declared capacitated in mind, then the voided contract can be reversed and once again valid. Individuals that are 18 or older can make legal decisions based on their:

  • Health
  • Safety
  • Welfare

If a person is under the legal age, but in the military, married, or emancipated by a court, he or she can make the same legal decisions as a legal adult.

Determining Incompetency

Once the court determines that someone is legally incapacitated, it can appoint a conservator or guardian to handle the person's belongings and make sure their day-to-day needs are met. A person who is intoxicated is also considered incompetent, so whatever contract that individual makes is not valid. A marriage can be annulled if one person was legally incompetent at the time of the marriage.

Incompetency can be determined by:

  • Age (under 18).
  • Mental capacity, such as insanity,
  • An already existing marriage.

You must also be legally competent to put a will into effect. The creator of a will must be of "sound mind." This means the testator must be competent to write the will, even though this can be questioned once the will is given.

Worker's Compensation

Legal incapacity also includes people who are under:

These people cannot work their jobs due to:

  • Illness (including mental illness).
  • Disabilities from birth onward.
  • Intellectual disabilities.
  • Advanced age.
  • Physical injury.

A will's legality can be questioned if the person does not demonstrate testamentary capacity.

Testamentary Capacity

Testamentary capacity means someone is legally competent to complete a will. A person not mature enough to make decisions for him or herself or a binding agreement does not have capacity. A guardian can handle these matters if a person is a minor or intellectually disabled. A person who cannot stand trial is also considered to have a legal incapacity. "Legally incompetent" is widely used to refer to an individual with physical or mental disabilities, although "incompetent" is a specific title for legal matters.

Someone who is legally incompetent cannot take part in legal matters. A person who does not understand why he or she has been charged with a crime is legally incompetent.

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