You need to be at least 21 years old and of sound mind to write a will. There is no need for your will to be drafted, approved or witnessed by a lawyer as long as your will fulfils the legal requirements. To be of a sound mind or have the testamentary capacity:

1. You should understand the nature of the act and what the consequences are;
2. You know and approve the contents of the will, nature and extent of properties;
3. You know who your beneficiaries are and can appreciate their claims on your properties; and
4. You are free from an abnormal state of mind that might distort feelings or judgements relevant to making the will.