Short answer. No. Legitimate children inherit from a parent without distinction as to sex or age, and expressly even if they come from different marriages. Children of the first marriage and children of the second stand on exactly the same footing, and an adopted child succeeds in the same manner as a legitimate child.
What the law says
Legitimate children and their descendants succeed the parents and other ascendants, without distinction as to sex or age, and even if they should come from different marriages.
Civil Code, Article 979 — Legitimate Children and Descendants. Read the full provision →
The rule was written for exactly this situation
Families in this position often assume that the household the parent died in must count for more, or that the eldest, or the son, or the child who cared for the parent has a stronger claim. The provision closes all three arguments in a single sentence. Legitimate children succeed without distinction as to sex or age, and the article then adds the phrase that decides your question: even if they should come from different marriages. Whether a child was born in 1985 to the first wife or in 2005 to the second makes no difference to the size of the share. The law treats them as one class of heirs and divides equally among them.
Descendants and adopted children
Two extensions matter in practice. First, the article covers legitimate children and their descendants. If one of the children died before the parent, that child's own children are not simply cut out; the line continues downward, taking the share the deceased child would have received rather than each grandchild counting as a full child. Second, an adopted child succeeds to the property of the adopting parents in the same manner as a legitimate child. A half-sibling by adoption is therefore not a lesser heir. These points often decide real disputes, because families tend to count heads at the funeral rather than trace the line.
What the equal-shares rule does not reach
Equality among the children does not mean the children take everything. A surviving spouse of the later marriage is a separate compulsory heir with her own share, and that is frequently what is really being felt when one branch complains the other received more. Before any inheritance is divided at all, the property regime of each marriage must be settled, so that what belonged to the surviving spouse as her half of the conjugal or community property is separated out and never enters the estate. Debts, taxes and expenses come off before distribution. A will can also assign the free portion unequally — what it cannot do is impair the legitime.
Where the fight usually really lies
In practice the dispute is rarely about the equality rule and almost always about status and paperwork: whether the second marriage was valid at all, whether a particular child is legitimate, legitimated, adopted or non-marital, and which properties actually belonged to the deceased. Gather the primary documents early — marriage certificates, birth certificates, adoption or legitimation records, titles, and tax declarations — because the whole computation turns on them. If you cannot agree, the estate can be settled judicially. What the outcome will be depends on those documents and on the particular facts, and no one can responsibly promise a result in advance.
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.
- Ilocos Norte Electric Cooperative vs. Gynthia Gertrudes Andres-Ranjo, Elma Andres Maran On, Represented By Her Husband, William G. Maranon, G.R. No. 200544, August 17, 2022 — read the decision on LawPhil →
- The Roman Catholic Bishop of Tuguegarao vs. Florentina Prudencio, et al, G.R. No. 187942, September 7, 2016 — read the decision on LawPhil →
- Napoleon D. Neri, et al. vs. Heirs of Hadji Yusop Uy and Julpha Ibrahim Uy, G.R. No. 194366, October 10, 2012 — read the decision on LawPhil →