A person's ability to create a legally valid will may be uncertain where that person's sound judgment is affected by mental disabilities. In order to possess the so-called 'testamentary capacity' to validly create a will, a person must be of sound mind, memory and understanding.

The case of Banks v Goodfellow establishes that a person will have 'testamentary capacity' if, at the time of creating or amending the will, he/she:

  • understands the nature of the will and its effects;
  • understands  the extent of the property being disposed of by the will;
  • comprehends and appreciates the claims of various people under the will; and
  • is free from any mental disorder or insane delusion influencing the disposal of his/her assets in a way which would not have been made if his/her mind was sound.

Courts presume elderly people have testamentary capacity when making or changing wills. In many instances, however, the testamentary capacity of an elderly testator will be uncertain when he/she becomes frail, falls ill, or begins to show signs of dementia or Alzheimer's disease. To complicate matters further, sometimes a person can temporarily recover testamentary capacity so as to have capacity to make a valid will.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.