Short answer. Either one. Under the Rules of Court, when both spouses have died, the conjugal partnership (or community property) is liquidated in the testate or intestate proceedings of either spouse's estate — the family is not required to open two separate estate cases just to settle what they owned together.
What the law says
When the marriage is dissolved by the death of the husband or wife, the community property shall be inventoried, administered, and liquidated, and the debts thereof paid, in the testate or intestate proceedings of the deceased spouse.
Rule 73, Section 2 — Where estate settled upon dissolution of marriage. Read the full provision →
What the law says
If both spouses have died, the conjugal partnership shall be liquidated in the testate or intestate proceedings of either.
Rule 73, Section 2 — Where estate settled upon dissolution of marriage. Read the full provision →
The general rule when one spouse dies
Rule 73, Section 2 starts with the ordinary situation: when a marriage is dissolved by the death of the husband or wife, the community property is inventoried, administered, and liquidated, and its debts paid, in the testate or intestate proceedings of the deceased spouse. In other words, whatever the couple owned together during the marriage gets sorted out inside the same court proceeding that settles the deceased spouse's individual estate, rather than in a separate liquidation case filed on its own.
What changes when both spouses have died
The rule then directly addresses your situation: if both spouses have died, the conjugal partnership is liquidated in the testate or intestate proceedings of either. This means the family does not need to open, or is not forced to choose between, two separate estate proceedings just to settle the property regime the couple shared. Whichever spouse's estate proceeding is opened — whether that is because a will exists for one of them, or heirs simply file for one parent's estate first — the liquidation of the conjugal partnership can take place inside that proceeding.
Why this matters for the heirs
In practice, this spares the heirs from running two parallel estate cases that would both need to account for the same conjugal or community assets, which could otherwise produce duplicated work, inconsistent inventories, or even conflicting court orders over the same property. Once the conjugal partnership is liquidated within whichever estate proceeding is opened, the net conjugal assets are divided between what belonged to each spouse, and each spouse's share then becomes part of that spouse's own estate to be distributed to the heirs.
What this rule does not decide
The rule tells you which proceeding the liquidation happens in — it does not, by itself, resolve who the heirs are, how much each heir eventually receives, or how any individually-owned property is distributed. Those questions still depend on whether either parent left a will, and on the ordinary rules governing intestate succession if they did not. The rule's function is narrower and procedural: it fixes the venue for liquidating what the couple owned together once both of them are gone.