1) Core Rule: Upon Death, Ownership Passes—But Usually as Co-Ownership

In Philippine law, succession opens at the moment of death, and the rights to the inheritance are transmitted to the heirs from that moment (Civil Code, Art. 777; see also Art. 774 on succession).

In most ordinary situations (no completed partition yet), what the heirs receive immediately is not exclusive ownership of specific lots or “my part of the house,” but an “ideal” or undivided share in the hereditary estate. Practically, the heirs become co-owners of the inherited property (Civil Code co-ownership provisions, especially Arts. 484–501).

Implication:

A single heir typically cannot sell the entire inherited property as if solely owned without the others’ consent.
An heir generally can sell only what they actually own at that time—usually an undivided interest (ideal share), not the whole property.

2) Two Big “Stages” That Affect Sale Validity

A. Before Settlement/Partition (Unsettled Estate / Co-Ownership Stage)

While the estate is unpartitioned, each heir’s interest is commonly undivided. This stage is where most “sold without consent” disputes happen.

B. After Settlement/Partition (Specific Portions Allocated)

After a valid partition (judicial or extrajudicial), an heir may become the exclusive owner of a specific property or lot, and can then sell that specific property on their own—subject to any other legal limits (e.g., family home issues, liens, encumbrances).

3) What a Single Heir May Legally Sell Without the Others’ Consent

(1) Sale of the Heir’s Undivided Share (Ideal Share) — Generally Allowed

Under Civil Code Art. 493, a co-owner may alienate (sell), assign, or mortgage their share, even without the consent of the other co-owners.

Effect:

The buyer becomes a co-owner with the remaining heirs, stepping into the seller’s shoes.
The sale is valid only up to the seller’s undivided interest, not the entire property.

Common misunderstanding: A deed may say “I sell the property” (the whole lot), but if the seller is only a co-owner, the law generally treats it as effective only for the seller’s share—unless the deed and surrounding circumstances show a different arrangement and later partition cures the defect for a specific portion (discussed below).

(2) Sale of a Specific Portion of an Unpartitioned Property — Risky / Usually Not Enforceable as to Specificity

If the property is still co-owned and unpartitioned, a selling heir cannot reliably convey a determinate part (e.g., “the rear half,” “100 sqm on the left”) as exclusive property, because that portion may not end up being allocated to them in partition.

Typical legal result:

The buyer may acquire only the seller’s undivided share, not exclusive title to that specific portion, unless partition later awards that portion to the seller (or the co-heirs later ratify/agree).

(3) Sale of Hereditary Rights to a Stranger — Allowed, but Triggers Co-Heirs’ Right of Redemption

An heir may sell/assign hereditary rights (their share in the inheritance) even before partition. But if the sale is to a stranger (not a co-heir), Civil Code Art. 1088 grants the other co-heirs a right of redemption.

Key points of Art. 1088 (co-heirs’ redemption):

Applies when an heir sells hereditary rights to a stranger before partition.
Other heirs may redeem the rights within one (1) month from receiving written notice of the sale.
The redemption is typically at the price paid (and related terms), subject to legal nuances.

Practical significance: Buyers who purchase from a lone heir during the unpartitioned stage face a real risk that the other heirs will redeem.

4) What a Single Heir Generally Cannot Sell Without Others’ Consent

(1) Sale of the Entire Inherited Property as Sole Owner — Invalid as to Others’ Shares

If one heir signs a deed selling 100% of a property that is actually co-owned by several heirs, the sale is generally:

Valid only to the extent of the seller’s share, and
Ineffective/invalid as to the shares of the non-consenting heirs.

In short: one heir cannot dispose of what they do not own.

(2) Sale Using an Extrajudicial Settlement (EJS) Without All Heirs — Usually Defective and Vulnerable

For intestate estates (no will) or even testate estates where allowed, heirs often use extrajudicial settlement under Rule 74, Section 1 of the Rules of Court. This is a common path to transfer title at the Registry of Deeds.

Rule 74, Sec. 1 basics (high-level):

Extrajudicial settlement is allowed when the decedent left no will and no debts (or debts are settled), and
The heirs execute a public instrument, typically requiring participation of the heirs entitled to the estate; publication requirements also apply.

If not all heirs participate/consent:

The settlement may not bind omitted heirs and is often attacked as invalid or ineffective as against them.
Any subsequent sale relying on that defective settlement becomes high-risk and can be challenged.

Common fraud pattern: A person executes an EJS falsely claiming to be the only heir (or omitting heirs), then sells and transfers title. This often leads to suits for annulment, reconveyance, damages, and sometimes criminal exposure.

(3) Sale When the Estate Is Under Court Administration (Judicial Settlement)

If there is a pending judicial settlement (executor/administrator appointed), estate properties are typically under custodia legis (under the court’s control). Sales of estate property generally require compliance with procedural rules and court authority.

Practical effect: A unilateral sale by an heir (or even by an administrator without authority) can be set aside, and buyers can be dragged into litigation.

5) Important Related Rules That Often Change the Analysis

A. Conjugal / Community Property and the Surviving Spouse

Many “inherited property” disputes are really about marital property:

If the decedent was married, the property might be:
- Conjugal Partnership of Gains (Family Code rules) or
- Absolute Community of Property, depending on marriage date and regime,
- or exclusive property of the decedent.

Before anything is “inherited,” the marital partnership/community must be liquidated: the surviving spouse’s share is not inheritance; it’s their own property.

Consequence: A child/heir selling “the whole house” without the surviving spouse’s participation may be doubly defective: the seller is not disposing only of other heirs’ shares, but also of the spouse’s property interest.

B. Minors / Incapacitated Heirs

If any heir is a minor or legally incapacitated, disposing of their property interests typically requires special protections (often including court approval/guardianship requirements). Transactions ignoring these safeguards are particularly vulnerable.

C. The Family Home

If the property qualifies as a family home, special protections may apply (Family Code provisions). While details depend on the specific facts (ownership, beneficiaries, debts, etc.), family home status can complicate execution, disposition, and enforcement.

6) What Happens to the Buyer?

A. Buyer Purchases Only an Undivided Share (Best-Case Scenario for Validity)

If the deed and circumstances support the interpretation that the heir sold only their share, the buyer becomes a co-owner.

Rights of the buyer as co-owner:

May demand partition (Civil Code Art. 494: generally, no co-owner is obliged to remain in co-ownership).
Shares in benefits and charges proportional to their share.
Must respect other co-owners’ rights.

But: the buyer cannot unilaterally evict other co-owners or claim exclusive possession of specific parts absent partition/authority.

B. Buyer Thinks They Bought the Whole Property (Most Litigious Scenario)

If the buyer paid for “100%” but the seller owned only “25%,” the buyer can:

Face claims by other heirs for reconveyance/recognition of their shares,
Seek remedies against the seller (refund, damages, rescission, breach of warranty of title, fraud-based claims),
Possibly be met with co-heirs’ redemption rights (Art. 1088 or co-ownership redemption in some settings).

C. Registered Land and “Good Faith” Issues

In Torrens title scenarios, buyers often invoke being an innocent purchaser for value. Whether that protects the buyer depends heavily on the pathway by which title was transferred and whether the seller was a registered owner—and whether the underlying instrument is void (e.g., forged) or merely voidable.

Practical reality: Cases involving omitted heirs, fraudulent settlements, or forged instruments are frequently litigated and fact-intensive. Buyers relying solely on a “clean title” without checking the estate documents and heirship risk being caught in a costly title dispute.

7) Remedies of Non-Consenting (or Omitted) Heirs

Non-consenting heirs typically have several overlapping remedies, depending on facts:

A. Civil Actions

Action to declare the sale void/ineffective as to their shares
Reconveyance (to recover property wrongfully transferred)
Annulment/nullification of documents (e.g., EJS, deed of sale)
Partition (to separate shares and clarify ownership)
Damages (actual, moral, exemplary, attorney’s fees where justified)
Injunction to stop further transfer or construction
Annotation of lis pendens (to warn third parties of a pending claim)

B. Rule 74 Protections

Rule 74 contains protections for persons prejudiced by extrajudicial settlement arrangements. Omitted heirs commonly rely on these concepts to argue that an extrajudicial settlement and transfers made under it do not bind them.

C. Criminal Exposure (Fact-Dependent)

If the transaction involved deception, falsified heirship, forged signatures, or fabricated documents, criminal complaints may arise (e.g., falsification, estafa), depending on the evidence.

8) Practical “Red Flags” in Transactions Involving Inherited Property

If you are evaluating whether a sale is vulnerable, these facts frequently matter:

Was there a settlement/partition? If yes, was it valid and properly executed?
Were all heirs identified and included? Any omitted heir is a major risk.
Was the decedent married? Was the marital property regime properly handled?
Were estate taxes and transfer requirements complied with? Noncompliance can block or complicate registration, and sometimes signals shortcuts.
Is any heir a minor/incapacitated? Extra legal steps may be required.
Is the seller claiming to be “sole heir”? Verify carefully.
Are there multiple deeds in quick succession (EJS → sale → transfer)? Often seen in fraudulent sequences.
Is the property under court settlement/administration? Court authority may be required.

9) Common “Truths” Summarized

One heir cannot validly sell the entire inherited property (100%) without the others’ consent when ownership is still shared.
One heir can generally sell their undivided share, making the buyer a co-owner (Civil Code Art. 493).
Selling hereditary rights to a stranger before partition can trigger co-heirs’ one-month redemption right upon written notice (Civil Code Art. 1088).
Extrajudicial settlements that omit heirs or lack proper participation are highly attackable, and downstream buyers inherit that risk (Rule 74).
Where there is court administration, sales of estate property typically require court authority; unilateral sales are vulnerable.
Disputes are often resolved through annulment/reconveyance/partition, and can include damages and, in fraud cases, criminal liability.

10) If You’re Dealing With an Actual Case

Because outcomes can turn on details (title history, documents used, presence of omitted heirs, marital regime, minors, court proceedings, notice requirements, and timing), it’s usually wise to have a Philippine lawyer review:

the title (and its transfer history),
the death certificate and proof of heirship,
any EJS/partition documents,
the deed of sale and any SPA/authority documents,
tax clearances and Registry of Deeds annotations.

If you want, describe the fact pattern (how many heirs, whether there was an EJS/partition, whether the decedent was married, and what exactly was sold), and the likely legal posture and best remedies can be mapped out more precisely.