I. Basic framework: how inheritance works in the Philippines

In the Philippines, inheritance is governed mainly by the Civil Code and the Family Code. When a grandmother (the “decedent”) dies, her properties are transmitted to her heirs either:

By will – called testate succession; or
Without a will – called intestate succession.

Two concepts are absolutely crucial to understand grandchildren’s rights:

Compulsory heirs – persons whom the law protects by reserving for them a fixed part of the estate (the legitime). They cannot be deprived of this portion except for very specific grounds (valid disinheritance).
Right of representation – the legal mechanism that allows grandchildren to “step into the shoes” of their parent (who was a child of the grandmother) when that parent can no longer inherit.

II. Who are the grandmother’s compulsory heirs?

In general, the possible compulsory heirs of a grandmother are:

Her legitimate children and other legitimate descendants
- This includes legitimate grandchildren, but generally only when the children (their parents) are no longer able to inherit (more on that later).
Her illegitimate children
Her surviving spouse (for example, the grandfather, or a second husband)
In some cases, her legitimate parents or ascendants – but only if she leaves no descendants. If there are children or grandchildren, the parents/grandparents are generally excluded from the legitime.

Key point for grandchildren: Grandchildren are part of the class “descendants.” They become active heirs in two main ways:

As direct compulsory heirs (when they are the closest living descendants, e.g., all her children have already died), or
By right of representation (they inherit the share that would have gone to their deceased/disinherited/incapacitated parent).

III. When do grandchildren inherit from their grandmother?

1. Directly (as closest living descendants)

If, at the time the grandmother dies:

All her children have already died, OR
None of her children are qualified to inherit (e.g., all disinherited or all incapacitated),

then the grandchildren become the primary compulsory heirs in the line of descendants. They do not “represent” anyone here; they inherit in their own right because they are now the nearest descendants.

In intestate succession, they will divide the estate among themselves, subject to the rights of any surviving spouse and any other compulsory heirs (such as illegitimate children of the grandmother, if any).

2. By right of representation

This is the most common scenario people have in mind when asking about a grandchild’s rights.

Right of representation occurs when:

The parent (a child of the grandmother) has:
- predeceased the grandmother (died earlier), or
- been disinherited by the grandmother through a valid disinheritance, or
- is incapacitated to inherit (for example, due to unworthiness under the Civil Code),

and

The grandchild is alive (and legally capable of inheriting) at the time the grandmother dies.

The law then allows the grandchild to stand in place of that parent and receive the same share that the parent would have received if that parent could inherit.

Representation is always by line or “stirpes” – grandchildren in the same line divide among themselves the share of their parent.

Example (intestate, simplified)

Grandmother dies, leaving:
- Child A (alive)
- Child B (already dead)
- B’s children: G1 and G2 (grandchildren of the grandmother)

In intestate succession among descendants:

The estate is divided into two “branches” (stirpes):
- One branch for Child A
- One branch for Child B’s line

Child A gets 1/2. The other 1/2 – which would have gone to Child B – is shared by G1 and G2 equally, so each gets 1/4.

If there is also a surviving spouse of the grandmother, the spouse will also have a share; the descendants’ collective shares and the spouse’s share are computed according to the Civil Code rules. The exact fractions become more technical, but the principle of representation within each branch remains the same.

IV. Testate vs intestate: how it changes grandchildren’s position

A. Intestate succession (no will)

If the grandmother dies without a valid will, the law provides a fixed order of heirs. When there are descendants, succession generally starts and ends with them, plus any surviving spouse.

Children alive at the time of death inherit in their own right.
Grandchildren inherit:
- In representation of their deceased/disinherited/incapacitated parent, or
- Directly (as nearest descendants) if no child survives.

The shares:

Are distributed by branch (per stirpes) and then divided equally within each branch.
Are adjusted further if there is a surviving spouse, and/or illegitimate descendants.

B. Testate succession (with a will)

A grandmother may make a will leaving property to particular persons, including or excluding grandchildren by name.

However, even with a will, the law protects compulsory heirs through the legitime:

Legitimate descendants (children and grandchildren) together are entitled to a certain fixed portion of the estate that the grandmother cannot impair by will.
The rest is the free portion, which she can freely dispose of (to anyone, including some grandchildren, charities, friends, etc.).

Thus:

If a grandchild is a compulsory heir (because they represent a deceased child or are the nearest descendants), the grandmother cannot effectively cut them off completely. Any testamentary provisions that reduce their legitime can be reduced (inofficious donations).
If a grandchild is not a compulsory heir in the circumstances (e.g., the grandchild’s parent is still alive and is a compulsory heir), the grandmother may choose to include or not include that grandchild in the free portion.

V. Special issues about grandchildren

1. Legitimate vs illegitimate grandchildren

The law distinguishes between:

Legitimate grandchildren – born to legitimate children of the grandmother (or legitimated by subsequent marriage, etc.).
Illegitimate grandchildren – born outside of marriage to a child of the grandmother, but legally recognized (or filiation otherwise established).

Some key points:

Both legitimate and illegitimate descendants can have inheritance rights, but their relative shares differ, and their ability to represent their parents up the line can be subject to additional rules.
Generally, the share of an illegitimate child (and by extension their line) is less than that of a legitimate child’s line.
Filiation must be legally established (e.g., recorded in the birth certificate, acknowledgment, court decision). Mere biological relationship is not enough for succession rights under Philippine law.

Because the combination of:

legitimate and illegitimate lines,
testate vs intestate succession, and
the presence/absence of a surviving spouse,

creates complex computations, it is wise to seek individual legal advice when illegitimacy is involved.

2. Adopted grandchildren

There are two main situations:

The grandmother adopts a child herself
- That adopted child becomes, for purposes of succession, generally equivalent to a legitimate child of the grandmother (subject to the adoption law in force at the time it was granted).
- The children of that adopted child are then the grandmother’s grandchildren in law, and inheritance rights follow the same logic as with blood grandchildren.
The grandmother’s child is adopted by someone else
- The effect on succession may depend on the type of adoption and the law in force when granted. In some cases, adoption can sever or significantly alter legal ties to the biological family for succession purposes.

Because adoption law has evolved, exact rights in older or foreign adoptions can be nuanced and should be examined case by case.

3. Step-grandchildren

A step-grandchild (e.g., the grandchild of the grandmother’s spouse from another relationship, with no legal adoption) generally:

Has no automatic right to inherit from the grandmother by operation of law.
Can only inherit from her:
- If she expressly includes them in a will (as a voluntary heir, legatee, or devisee), or
- Through donations during her lifetime.

They are not compulsory heirs.

VI. Effect of surviving spouse and property regime on what grandchildren can receive

Before talking about “shares,” it is crucial to understand what actually forms part of the grandmother’s estate.

1. Community or conjugal property vs exclusive property

Depending on the property regime between the grandmother and her spouse (under the Family Code or older laws):

Absolute community of property (ACP) – usually applies to marriages under the Family Code (default in many cases). Most properties acquired during the marriage are common.
- Only the grandmother’s share in the community (usually 1/2) becomes part of her estate.
Conjugal partnership of gains (CPG) – older regime for pre-Family Code marriages or where agreed upon.
- Upon death, the conjugal partnership is liquidated; the surviving spouse gets his share of the net conjugal gains (typically 1/2), and the grandmother’s share becomes her estate.
Exclusive / paraphernal property – properties owned exclusively by the grandmother (e.g., property acquired before the marriage, inheritances with stipulation, etc.).

Grandchildren do not inherit the entirety of a property that was jointly owned. They only succeed to the grandmother’s share of that property.

2. Surviving spouse’s share

Whether in testate or intestate succession, the surviving spouse (e.g., the grandfather or step-grandfather) is almost always a compulsory heir when he survives the grandmother.

Thus, grandchildren’s shares are computed after recognizing:

the surviving spouse’s conjugal/community share, and
the surviving spouse’s inheritance share as compulsory heir in the estate.

Grandchildren can never legally take the portions that correspond to the property rights of the surviving spouse.

VII. Grandchildren and disinheritance, unworthiness, and preterition

1. Can the grandmother “cut off” grandchildren by disinheriting their parent?

If the grandmother validly disinherits one of her children (for a cause expressly allowed by law), that child loses their right to inherit. However:

Right of representation still operates in favor of that child’s descendants, unless the law specifically treats them as also affected (for example, if the ground for disinheritance logically extends to the line).

In a typical case, grandchildren may still inherit by representation despite their parent being disinherited, but this is a technical area, and details matter (ground, wording of the will, etc.).

2. Unworthiness to inherit

Certain acts (e.g., attempting to kill the decedent, serious falsification, etc.) can make an heir unworthy. If a child of the grandmother is unworthy:

That child may not inherit, but
The child’s descendants (grandchildren) may still inherit by representation, unless they also committed acts that make them unworthy.

3. Preterition (complete omission of a compulsory heir)

Preterition occurs when a compulsory heir in the direct line (e.g., a child or grandchild who is a compulsory heir) is completely omitted from a will, whether intentionally or by mistake.

Effects (simplified):

The institution of heirs in the will may be annulled totally or partly, reviving intestate rules to protect the omitted compulsory heir’s legitime.
If a grandchild is already a compulsory heir (e.g., representing a deceased child) and is preterited, the will’s dispositions can be seriously affected.

Thus, a grandmother cannot simply “forget” a grandchild who has become a compulsory heir, without consequences for the validity of her will’s dispositions.

VIII. How grandchildren assert their inheritance rights

Once the grandmother dies, her estate must be settled. Grandchildren who believe they are heirs should be aware of the usual paths:

1. Extrajudicial settlement (no court case)

This is possible if:

The grandmother left no will;
All heirs are of legal age (or minors properly represented);
There are no known debts (or debts are settled);
The heirs agree on how to divide the property.

The heirs (including grandchildren who are heirs) may execute a Deed of Extrajudicial Settlement of Estate, typically notarized, and comply with:

Publication requirements;
Estate tax settlement with the BIR;
Transfer of title with the Registry of Deeds / LTO (for vehicles), etc.

If grandchildren are compulsory heirs (e.g., representing a deceased child), they must be included, or they can later challenge the deed.

2. Judicial settlement (court proceedings)

Grandchildren may go to court when:

There is a will (probate is required).
There is disagreement among heirs.
Some heirs are omitted.
There are complicated debts and claims.

They may file or participate in:

Testate proceedings (with a will); or
Intestate proceedings (without a will),

and assert their status as:

Heirs in their own right (as nearest descendants), or
Heirs by representation (standing in for a deceased/disinherited/incapacitated parent).

The court will determine heirship, identify the estate, pay debts, and eventually order partition among heirs.

IX. Practical documentation and proof for grandchildren

To enforce their rights, grandchildren commonly need:

Proof of death of the grandmother (death certificate).
Proof of relationship:
- Birth certificates showing the line from the grandmother to the parent to the grandchild.
Proof of filiation for illegitimate grandchildren (documented acknowledgment, court decisions, etc.).
Marriage certificates (to confirm property regimes and identity of surviving spouse).
Titles, tax declarations, or other documents identifying properties as belonging to (or co-owned by) the grandmother.

Without proper documentation, rights may exist in theory but can be very hard to exercise in practice.

X. Planning perspective: what grandmothers and grandchildren should keep in mind

For grandmothers

You cannot deprive compulsory heirs (including qualifying grandchildren) of their legitime except by valid disinheritance under the Civil Code.
Wills should be carefully drafted to:
- Respect legitimes of compulsory heirs.
- Use the free portion to favor particular grandchildren (e.g., those who have special needs or whom you particularly wish to benefit).
Think about:
- Clarifying recognition of illegitimate descendants.
- Avoiding preterition (unintended omission of compulsory heirs).
- Coordinating with the surviving spouse’s property rights.

For grandchildren

Your right to inherit from a grandmother depends heavily on:
- Whether your parent (her child) survives, has been disinherited, or is unworthy.
- Your legal status (legitimate, illegitimate, adopted, etc.).
- Whether the grandmother left a will and who the other heirs are (children, spouse, etc.).
If you are the child of a deceased child of the grandmother, you likely have rights by representation, but:
- Your exact share depends on many variables.
- You may need legal assistance to compute your legitime and assert it in probate or settlement proceedings.

XI. Final note

The rules on grandchildren’s inheritance rights in a grandmother’s estate in the Philippines are built around:

The priority of descendants,
The protection of compulsory heirs through legitimes, and
The mechanism of representation, allowing grandchildren to inherit in place of a deceased or disqualified parent.

The broad principles are stable, but exact computations and outcomes can become quite technical once you factor in:

Surviving spouse,
Legitimate and illegitimate lines,
Adoption,
Will provisions and donations,
Property regimes and debts.

For specific family situations or to compute concrete shares, it is prudent to consult a Philippine lawyer who handles succession and estate settlement, bringing all relevant documents (birth and marriage certificates, titles, and any will or deeds).