Short answer. Not entirely, but not entirely voided either. Article 918 annuls the institution of heirs only to the extent your defective disinheritance prejudices you as the disinherited compulsory heir. Devises, legacies, and other testamentary dispositions in the will remain valid, so long as they do not impair your legitime.
What the law says
Disinheritance without a specification of the cause, or for a cause the truth of which, if contradicted, is not proved, or which is not one of those set forth in this Code, shall annul the institution of heirs insofar as it may prejudice the person disinherited; but the devises and legacies and other testamentary dispositions shall be valid to such extent as will not impair the legitime.
Civil Code, Article 918 — Defective Disinheritance. Read the full provision →
What makes a disinheritance defective in the first place
Article 918 lists the ways a disinheritance can fail: "without a specification of the cause, or for a cause the truth of which, if contradicted, is not proved, or which is not one of those set forth in this Code." So a disinheritance is defective if your father did not state a cause at all, if he stated one but it turns out not to be true when you contest it, or if the cause he gave is not among those the Code actually recognizes as valid grounds. Any of these problems is enough to trigger the consequences the article sets out.
Only the institution of heirs is annulled, and only partly
The consequence is targeted, not sweeping. Article 918 provides that a defective disinheritance shall annul the institution of heirs insofar as it may prejudice the person disinherited. The will is not thrown out wholesale. What gets undone is the naming of heirs, and even that is undone only to the extent it hurts you, the person who was wrongly disinherited. If the institution of other heirs does not encroach on what you are entitled to, that part of the will can remain untouched.
Devises, legacies, and other dispositions can survive
The article draws a further, important line for gifts of specific property: the devises and legacies and other testamentary dispositions shall be valid to such extent as will not impair the legitime. Specific bequests your father made to others in the will are not automatically wiped out by the defective disinheritance. They remain valid, but only up to the point where honoring them would eat into what the law reserves for you as a compulsory heir. Beyond that point, they yield to protect your legitime.
What this means for your father's will
In practice, a defective disinheritance against you does not collapse the whole will. It reopens the question of the institution of heirs to the extent your share was affected, while leaving devises, legacies, and other dispositions standing wherever they do not cut into your legitime. Working out exactly which provisions survive and which give way requires comparing what the will actually left to others against what your legitime is worth, since the article ties the outcome directly to that comparison rather than to the will as a whole.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Ana Maria C. Manguerra vs. Ma. Patricia Concepcion E. Manguerra-Aberasturi, et al, G.R. No. 253426, November 29, 2022 — read the decision on LawPhil →