Testamentary freedom is a fundamental principle in Philippine succession law, but it is not absolute. The Civil Code of the Philippines (Republic Act No. 386) balances the testator’s right to dispose of his estate with the protection of compulsory heirs through the legitime. This article comprehensively discusses the grounds and rules for the revocation of wills and the disinheritance of compulsory heirs under Philippine law.

I. Revocation of Wills

A will is a personal, revocable act. Article 828 of the Civil Code provides that a will may be revoked by the testator at any time before his death. Any waiver or restriction of this right is void and without effect.

Modes of Revocation

Express Revocation by Subsequent Will or Codicil (Article 829)
A prior will is revoked by a later will or codicil that expressly revokes it or is inconsistent with its provisions. The subsequent instrument must itself be a valid will or codicil. Partial revocation is possible if only specific provisions are revoked.
Revocation by Physical Act (Article 830)
The testator may revoke the will by burning, tearing, cancelling, or obliterating it, or by performing any act that clearly shows the intention to revoke, done by the testator himself or by another person in his presence and by his express direction. For holographic wills, any act indicating intent suffices if done by the testator. The animus revocandi (intention to revoke) must be present.
Implied Revocation
A subsequent will that disposes of all or substantially all the property of the testator in a manner inconsistent with the prior will operates to revoke the earlier will by implication. If the later will does not completely dispose of the estate, only the inconsistent provisions are revoked.
Revocation by Operation of Law
Philippine law does not provide for broad automatic revocation upon marriage or birth of a child as in some foreign jurisdictions. However, the emergence of new compulsory heirs (such as after-born legitimate children) may trigger preterition rules (Article 854), which can annul the institution of heirs while leaving legacies and devises intact if not inofficious. Changes in family status under the Family Code may also affect related donations propter nuptias but do not automatically revoke a will.

Requirements for Valid Revocation

The testator must have testamentary capacity at the time of revocation.
For physical revocation, the act must be intentional and not accidental.
Revocation is not presumed; it must be clearly established.

Effects of Revocation

A revoked will loses its legal effect and cannot be probated unless it is revived. However, revocation of a will does not necessarily revoke legacies or devises if they are confirmed in another way.

Revival of Revoked Wills (Article 837)

A revoked will may be revived by the execution of a subsequent will or codicil that expressly revokes the revocation or by re-execution of the original will with the formalities required for its execution. Revival restores the will to its original effect, subject to any intervening changes.

Special rules apply to joint wills (generally prohibited under Article 818, except in limited cases for Filipinos abroad), mutual wills, and foreign wills probated under Rule 77 of the Rules of Court.

II. Disinheritance

Disinheritance is the express deprivation by the testator of the legitime of a compulsory heir for a just cause. It is a severe measure and is strictly construed by courts (strictissimi juris).

Compulsory heirs entitled to legitime include (Article 887):

Legitimate children and their descendants;
Legitimate parents and ascendants (in default of the above);
The surviving spouse; and
Illegitimate children (entitled to one-half the legitime of a legitimate child).

Requirements for a Valid Disinheritance (Articles 915–918)

It must be made in a valid will or codicil.
The disinheritance must be express.
The specific cause or ground must be stated in the will itself.
The stated cause must be one of those provided by law.
The cause must be true and proven if the disinheritance is contested. The burden of proof is on the person claiming the disinheritance is valid (usually the other heirs or executor).

If any requirement is not met, the disinheritance is null and void, and the compulsory heir is entitled to his or her legitime.

Disinheritance affects only the legitime. The disinherited heir may still receive property from the free portion if instituted as an heir thereto or given a legacy or devise.

Grounds for Disinheritance

A. Of Children and Descendants (Article 919)
The following are sufficient causes:
(1) When a child or descendant has been found guilty of an attempt against the life of the testator, his or her spouse, descendants, or ascendants;
(2) When a child or descendant has accused the testator of a crime for which the law prescribes imprisonment for six years or more, if the accusation has been found groundless;
(3) When a child or descendant has been convicted by a final judgment of adultery or concubinage with the spouse of the testator;
(4) When a child or descendant by fraud, violence, intimidation, or undue influence causes the testator to make a will or to change one already made;
(5) A refusal without justifiable cause to support the testator;
(6) Maltreatment of the testator by word or deed by the child or descendant.

B. Of Parents and Ascendants (Article 920)
Causes include:
(1) When the ascendant has been found guilty of an attempt against the life of the testator, his or her spouse, descendants, or ascendants;
(2) When the ascendant has accused the testator of a crime punishable by imprisonment of six years or more if groundless;
(3) When the ascendant has been convicted of adultery or concubinage with the spouse of the testator;
(4) Refusal without justifiable cause to support the testator;
(5) Maltreatment.

C. Of the Surviving Spouse (Article 921)
(1) When the spouse has been found guilty of an attempt against the life of the testator or their common children;
(2) When the spouse has been convicted of adultery or concubinage;
(3) When the spouse has refused without justifiable cause to support the testator;
(4) When the spouse has given cause for legal separation (cross-referenced with Articles 55–67 of the Family Code).

Illegitimate children are generally subject to the same grounds as legitimate children for disinheritance purposes.

Pardon, Condonation, and Reconciliation

If the testator expressly or impliedly pardons or reconciles with the heir after the cause arose, the disinheritance may be rendered ineffective. Condonation can be express (e.g., in a later will) or implied by acts showing forgiveness (e.g., continued support or cohabitation). The law favors reconciliation.

Distinction from Preterition and Unworthiness

Preterition (Article 854): The unintentional omission of a compulsory heir in the will. It annuls the institution of heirs but leaves legacies and devises intact unless inofficious. It is not disinheritance, which requires express statement.
Unworthiness (Articles 1027–1032): Certain heirs are disqualified by law (indignos) for grave offenses against the decedent (e.g., attempt on life, false accusation, adultery with spouse, etc.). This exclusion is automatic by operation of law and applies to both intestate and testate succession unless the decedent forgives in the will or before death. Disinheritance is an express testamentary act specifically targeting legitime.

Procedural Aspects

In probate proceedings, if disinheritance is contested, the proponent must prove the truth of the cause by preponderance of evidence. Philippine courts require clear and convincing proof for the grounds. Disinheritance clauses are interpreted strictly against the testator’s intent to disinherit.

The disinherited heir loses only the legitime but may participate in the free portion if provided. Disinheritance does not affect the heir’s right to other claims, like collation if donations inter vivos were made.