Challenge the Will based on capacity: if it can be shown that the will-maker lacked testamentary capacity, the Will may be found to be invalid. For example, if the will-maker has been declared as unable to manage their affairs by their doctor due to mental incapacity. Testamentary capacity can be challenged on three grounds:

• At the time of executing the Will, the will-maker did not understand that they were making a will;
• The will-maker did not understand that he or she was intending to dispose of property effective on his or her death; or
• At the time of signing the Will, the will-maker suffered from mental disorder.

This illustrates why it is important to organize your estate before you fall ill: you do not want to reach a point in sickness or mental decline where you are unable to explain your wishes to a lawyer. A mental status examination may be required to determine capacity.

Challenge the Will based on undue influence: if someone coerced the will-maker into making the Will in a way that favours them or their wishes, the Will may be found to be invalid. For example, a child convinces their parent to change their Will on their death bed to provide them with a higher percentage of the assets.

Challenge the Will based on unfair distribution of assets: the Wills, Estates and Succession Act confers a moral obligation on individuals to provide for their spouse and children. A child who receives nothing in their parent’s Will may apply to the court to have the assets redistributed so that they are provided for. To vary a Will, you must be an eligible applicant under the Wills, Estates and Succession Act. This inclues:

• The surviving spouse, of the same or opposite sex;
• The common-law spouse (in a marriage like relationship for at least two years prior to the death, including same-sex); or
• The child of the will-maker, including adopted children but not step-children.

Challenge the Will based on improper execution: there are a number of technical requirements that must be met to make a Will valid. If one of these conditions are not met, the Will may be challenged on this ground. For example, claims can be brought if the Will is not signed or witnessed. Conversely, the Court may choose to uphold the Will, despite the deficiencies, if it determines that it accurately reflects the wishes of the will-maker.

Challenge the Will based on a constructive trust: if you have provided unpaid work for the will-maker and were promised compensation, you may have a claim for the assets in the will, even if you have not been specifically provided for. This is called a constructive trust or unjust enrichment.

Challenges the validity of pre-death gifts: there are a number of ways that individuals may transfer items so that they do not form part of their estate on death, and thus are not subject to the terms of the Will. If assets are transferred incorrectly, or it is your belief that they were meant to form part of the estate, the pre-death gifts can be challenged as being part of the estate. An adult child may need to defend a transfer made to them by a parent, pre-death, as a gift. This applies to transfers of property or to a joint bank account.