(cf WPA 18)
(1) An alteration to a will after it has been executed is not effective unless the alteration--(a) is executed in the manner in which a will is required to be executed under this Part, or(b) is made by a minor by the authority of an order of the Court under section 16 and is executed in accordance with, and satisfies the requirements for such a will set out in, section 16 (5), or(c) is made for and on behalf of a person who does not have testamentary capacity by the authority of an order under section 18 and satisfies the requirements for such a will set out in section 23.
(2) Subsection (1) does not apply to an alteration to a will made by or at the direction of the testator, or signed by the Registrar under section 23, if the words or effect of the will are no longer apparent because of the alteration.
(3) If a will is altered, it is sufficient compliance with the requirements for execution if the signatures of the testator and of the witnesses to the alteration are made--(a) in the margin, or on some other part of the will beside, near or otherwise relating to the alteration, or(b) as authentication of a memorandum referring to the alteration and written on the will.
Note : The Interpretation Act 1987 defines
"sign" to include making a mark.