A will should be reviewed every few years to check it continues to meet the needs and circumstances of the testator. Some life events automatically revoke a will – see Registered relationships, marriage and separation.

A will should also be reviewed and updated as needed following significant life events such as a new or ended relationship, the birth or adoption of children, a change in circumstances of an executor or beneficiary (including relocation or death), a significant change in assets (such as buying or selling a house), and retirement.

A will that has been fully executed (signed and witnessed) cannot be altered, either by crossing out or writing in new clauses, unless the changes are executed in the same manner as a will [Succession Act 2023 (SA) s 16].

Small changes to a will may be made by making a codicil. A codicil is a separate document that adds to or changes an existing will.

A codicil must meet the formal requirements of a will (see Valid wills) and should refer to the original will and the date it was made. It need not be witnessed by the same people who witnessed the original will, but it must have a properly signed attestation clause.

Because of the formal requirements to make a codicil, often the easiest and simplest way to update a will is to make a new one. Making a new will automatically revokes any previous or existing wills made by the testator. It also eliminates the risk that a codicil may become separated from a will.