No obliteration, interlineation or other alteration made in any unprivileged will after the execution thereof shall have any effect, except so far as the words or meaning of the will have been thereby rendered illegible or undiscernible, unless such alteration has been executed in like manner as hereinbefore is required for the execution of the will:
Provided that: the will, as so altered, shall be deemed to be duly executed if the signature of the testator and the subscription of the witnesses is made in the margin or on some other part of the will opposite or near to such alteration, or at the foot or end of or opposite to a memorandum referring to such alteration, and written at the end or some other part of the will.
Legal Commentary & Landmark Judgments: Section 71
Section 71 regulates interlineations, obliterations, and alterations made after the execution of an unprivileged will, enacting that they have no legal effect unless executed and attested with the formalities required for a will.
To give legal effect to any post-execution alteration, the alteration itself must be executed in the exact manner required for the execution of a will under Section 63: the testator must sign and the attesting witnesses must attest in the margin or near the alteration, or at the foot of a memorandum referring to the alteration. If an alteration is not so signed and attested, the court must read the will in its original, unaltered form if the original words can still be deciphered on the face of the document.
Section 71 is a lethal weapon when challenging wills that exhibit hand-written insertions, whitener, or crossed-out paragraphs. Unless the margin adjacent to the alteration carries the signatures of both the testator and the two attesting witnesses, the court will ignore the alteration entirely. If a testator wishes to make changes, the only safe legal course is to execute a formal codicil or an entirely fresh will.