Bottom line: Nephews and nieces are not compulsory heirs in the Philippines. They inherit only (a) when the decedent leaves no descendants (children/grandchildren) and no ascendants (parents/grandparents) and there is no valid will, or (b) when they are named in a will to receive from the free portion. In intestate succession (no will), they usually take by representation of their deceased parent who was a brother or sister of the decedent, and their shares hinge on (i) whether there are surviving siblings, (ii) whether their parent was of the full blood or half blood, and (iii) whether a surviving spouse exists.

This guide explains when nephews/nieces inherit, how to compute their shares, special “iron curtain” limits involving illegitimacy, adoption effects, and practical documentation.

1) Where Nephews and Nieces Sit in the Order of Heirs

A. Testamentary succession (with a will)

Nephews/nieces can inherit if the will institutes them as heirs or gives them legacies/devices.
Their testamentary gifts are limited by the legitimes of compulsory heirs (descendants, ascendants, surviving spouse, and illegitimate children). A will cannot cut into these reserved shares.
If the will names only nephews/nieces and there are no compulsory heirs, they can take everything under the will.

B. Intestate succession (no will)

The law calls heirs in a fixed order. Nephews/nieces are called only after:

Descendants (children/grandchildren), then
Ascendants (parents/grandparents).

If there are no descendants and no ascendants, succession moves to the collaterals:

First in line among collaterals are brothers and sisters of the decedent.
Children of brothers/sisters (nephews/nieces) inherit by representation of their parent who predeceased the decedent or is disqualified.
If there are no living siblings, nephews/nieces can end up as the primary intestate heirs, each stepping into the place (the stirps) of their deceased parent-sibling of the decedent.

Representation stops at nephews/nieces. It does not extend to grandnephews/grandnieces in the collateral line.

2) Representation and Per Stirpes Sharing

When representation applies, nephews/nieces do not simply add up as individuals. They divide per stirpes—by “branch”:

Each deceased sibling of the decedent forms one branch (stirps).
All children of that deceased sibling share that branch equally.
A living sibling takes one full branch in his/her own right.

Example 1 (basic stirpital split): The decedent leaves no spouse, no descendants, no ascendants. He had:

Sister A (alive) – full blood
Brother B (deceased) – full blood, left two children B1 and B2 Total branches: 2 (A and B’s branch). Estate division: ½ to A, ½ to B’s branch → B1 and B2 get ¼ each.

3) Full-Blood vs Half-Blood Effects

Among brothers and sisters, a half-blood sibling (sharing only one parent with the decedent) typically receives half the share of a full-blood sibling. This difference carries through to representation:

If your parent (the decedent’s sibling) was half-blood, the branch you represent takes only half of what a full-blood branch would take.
If your parent was full-blood, your branch takes a full portion.

Example 2 (full vs half blood): Decedent leaves no spouse/descendants/ascendants.

Sister A (alive, full-blood)
Brother B (deceased, half-blood), left one child B1

Baseline: A’s full-blood branch = 1 unit; B’s half-blood branch = ½ unit. Normalize totals: 1 + ½ = 1.5 units. Shares: A gets 1/1.5 = 2/3; B’s branch gets 1/1.5 × ½? (equivalently 1/3), so B1 = 1/3.

4) Concurrence with a Surviving Spouse (Intestacy)

If there is no descendant and no ascendant, the surviving spouse shares the estate with brothers/sisters (and, by representation, nephews/nieces). The spouse’s exact fraction is set by statute and must be applied before distributing the remainder among the collateral branches. After carving out the spouse’s portion, apply the stirpital rules (and full/half-blood adjustments) to the residue.

Practice pointer: Always compute the spouse’s share first, then distribute the balance to siblings and their children by representation. When in doubt about the precise spouse fraction in your fact pattern, make both computations (the conservative and the generous to spouse) and show both results; the court will apply the correct one.

5) The “Iron Curtain” Rule on Illegitimacy (Collateral Bar)

There is no intestate succession between an illegitimate child and the legitimate relatives of his/her parents—and vice versa. This long-standing “iron curtain” rule has big consequences for nephews/nieces:

If the nephew/niece is illegitimate (child of your legitimate brother/sister) and the decedent is a legitimate relative of that parent (as an aunt/uncle), the illegitimate nephew/niece cannot inherit ab intestato from the decedent.
Likewise, a legitimate decedent cannot inherit intestate from an illegitimate nephew/niece, and an illegitimate decedent faces reciprocal bars with the legitimate relatives of his/her parents.

Effect on representation: Because the bar is between the illegitimate child and the legitimate relatives of the parent, the illegitimate nephew/niece cannot represent the legitimate parent to inherit intestate from the parent’s legitimate siblings.

Workarounds:

A will can give to an illegitimate nephew/niece from the free portion (respecting legitimes).
Where the family mix includes both legitimate and illegitimate lines, run the iron-curtain check before doing any stirpital math.

6) Adoption and Its Successional Effects

Under current adoption law, an adoptee becomes a legitimate child of the adopter for all civil effects, including succession; ties to the biological family are generally severed (with limited exceptions not relevant here).

A child of your adopted sibling is your legal nephew/niece for succession purposes.
Conversely, a biologically related nephew/niece of an adoptee may lose intestate rights through the adoptee if the legal tie was severed by adoption. Always identify whether the link is legal (post-adoption) or merely biological.

7) Disqualifications, Unworthiness, and Representation

A nephew/niece can represent a parent who is predeceased, incapacitated, disqualified, or unworthy (e.g., committed serious offenses against the decedent), provided no iron-curtain bar applies.
If a representing nephew/niece is also unworthy or renounces the inheritance, his/her own descendants do not step further in the collateral line (representation does not go beyond nephews/nieces).

8) Step-by-Step Computation Framework (Intestacy)

Screen out: Are there descendants or ascendants? If yes, nephews/nieces do not inherit by intestacy.
Identify spouse: If there is a surviving spouse, compute the spouse’s statutory share first.
List siblings: Mark each living sibling (full vs half-blood).
Form branches: For each deceased sibling, identify his/her children (nephews/nieces) who can represent.
Apply iron curtain: Exclude any nephew/niece barred due to illegitimacy vis-à-vis the decedent’s line.
Assign branch weights: Full-blood branch = 1; half-blood branch = ½.
Normalize and allocate the residual estate across branches based on weights.
Split each branch equally among the children within that branch.
Account for multiple estates or multiple informations only if relevant (e.g., conjugal/community property issues).

9) Illustrative Scenarios

Scenario A — Classic representation:

No spouse, descendants, or ascendants.
Siblings: S1 (alive, full), S2 (deceased, full; left C2a, C2b), S3 (deceased, half; left C3). Branch weights: S1 = 1; S2’s branch = 1; S3’s branch = ½. Total = 2.5. Shares:
S1 = 1/2.5 = 2/5
S2’s branch = 1/2.5 = 2/5, split: C2a = 1/5, C2b = 1/5
S3’s branch = ½ / 2.5 = 1/5 → C3 = 1/5

Scenario B — Only nephews/nieces remain:

No spouse, descendants, ascendants, or living siblings.
Two deceased full-blood siblings each left two children. Two equal branches → each branch takes ½, each child within a branch gets ¼.

Scenario C — With surviving spouse:

Spouse survives; no descendants/ascendants.
Collateral heirs: one living full-blood sister and one branch of a deceased full-blood brother (two children). Compute the spouse’s statutory share first; distribute the remainder: two equal branches—living sister gets her branch; the two nephews split the brother’s branch.

10) Are Nephews/Nieces Compulsory Heirs? (No.)

They have no legitime. A testator may exclude them entirely by will, subject only to protecting the legitimes of compulsory heirs (if any).
If there is no will and none of the nearer classes (descendants/ascendants) survive, they step in under the intestacy rules above.

11) Practical Proof and Paperwork

To claim as a nephew/niece—especially by representation—you typically need:

Civil registry documents: Birth certificates proving (i) the decedent’s parents, (ii) the parent-child link between the decedent and your father/mother (the sibling), and (iii) your own parentage.
Proof of death or disqualification of the parent-sibling you represent.
Status documents: Marriage/annulment/void declarations if relevant; adoption decrees where applicable.
Affidavits resolving name discrepancies or clerical errors.
Estate inventory and heirship proceedings (extrajudicial settlement when allowed, or intestate proceedings in court).

Extrajudicial settlement is available only if all heirs are of legal age (or represented) and there are no debts or the creditors are paid/assumed. Otherwise, file an intestate case for proper determination of heirs and shares.

12) Taxes and Liabilities (Quick Orientation)

The estate (not the heirs personally) owes estate tax before distribution. Heirs may become personally liable up to the value they received if the estate fails to settle taxes.
Documentary stamp taxes can apply to partitions and property transfers.
Heirs should coordinate with counsel and a tax practitioner to time and document payments, especially when assets are illiquid.

13) Common Pitfalls

Skipping the iron-curtain check → including barred illegitimate nephews/nieces in intestate computation.
Treating nephews/nieces as compulsory heirs → they are not.
Ignoring half-blood adjustments → overpaying a half-blood branch.
Extending representation beyond nephews/nieces → the law does not allow representation by grandnephews/nieces in the collateral line.
Misallocating before the spouse’s share → compute the spouse first in intestacy.
Adoption effects overlooked → verify whether the legal tie is via adoption (current) or biology (severed by adoption).

14) Quick Checklist for Lawyers and Families

Confirm no nearer heirs (descendants/ascendants).
Identify and compute the surviving spouse’s intestate share (if any).
Map the family tree: list living siblings; for deceased siblings, list their children.
Mark full-blood vs half-blood branches.
Apply the iron curtain and exclude barred lines.
Allocate per stirpes and then per capita within each branch.
Paper it: gather civil registry proofs, settle estate taxes, and choose the correct procedural path (extrajudicial vs court).

Final Takeaway

Nephews and nieces inherit primarily as substitutes for a deceased brother/sister of the decedent, only in intestacy, and only after clearing away nearer lines (descendants, ascendants) and the iron-curtain illegitimacy bar. Their exact shares depend on stirpital distribution, full vs half-blood weighting, and any surviving spouse’s prior cut. In testamentary succession, they rely on the free portion—and careful drafting is everything.

This is general information and not legal advice. For a concrete estate, have counsel verify family statuses, compute the spouse’s share, run the iron-curtain analysis, and finalize per stirpes distributions with supporting documents and tax clearances.