To make a valid Will you (the Testator) must:

• be at least 18 years of age;
• understand and approve the nature and effects of making a Will;
• understand the extent of the property you are disposing of in your Will;
• understand the claims to which you should give effect (e.g. the moral claims of family members); and
• be of sound mind, memory and understanding.

Where there are concerns that a Testator:

• does not understand the contents or effect of his or her Will;
• may be being unduly influenced by another person;
• shows signs of senility or dementia or that they are not of sound mind;
• is close to death; or
• has been significantly affected by a medical condition;

the Will should be witnessed by a qualified and practising medical practitioner. The medical practitioner should also sign a written opinion that the Testator has mental capacity. In making this assessment, it is common for a medical practitioner to carry out a Mini-Mental State Examination of the Testator. This examination is used by healthcare practitioners to check for cognitive impairment.

Where it is not practical to obtain a medical certificate, the lawyer drafting the Will can ask questions of the Testator designed to test their mental capacity.