I. Overview and governing concepts

When a person dies, the decedent’s rights, properties, and obligations not extinguished by death pass to heirs by succession. From the moment of death, the heirs generally become co-owners of the hereditary estate (the “estate” or “inheritance”) until partition. This co-ownership is a special kind of co-ownership: it is not created by contract, but by law (succession), and it exists while the estate remains undivided.

The key practical consequence is simple but often misunderstood:

Before partition, no heir can point to a specific house, lot, room, bank account, or particular item and say “this exact thing is mine.”
What an heir holds is an ideal or undivided share in the whole estate (or in a particular property that remains in co-ownership).

This “ideal share” is property. As such, it can generally be sold, assigned, donated, or mortgaged, subject to important limitations and protections for the other co-owners and for the estate’s proper settlement.

The “sale of an undivided inheritance share” therefore means a transfer by an heir of his/her hereditary rights or participation in the undivided estate (or of an undivided share in a specific estate property that is still held in common).

II. The legal framework (Philippine context)

The topic sits at the intersection of:

Succession law (Civil Code provisions on inheritance and hereditary rights, including partition and collation concepts), and
Co-ownership law (Civil Code rules on co-ownership, including alienation of shares, use and enjoyment, administration, and partition), plus
Property and obligations law (rules on sale, rescission, warranties, and registration), and
Procedural/settlement rules (judicial and extrajudicial settlement; estate obligations; rights of creditors; estate tax and documentary requirements).

You should think of the rules as answering four recurring questions:

What exactly is being sold? (An ideal share, not a specific thing—unless later partition awards it.)
Can the heir sell it without consent? (Generally yes for the share; no for the entire thing.)
What protections do other co-heirs have? (Legal redemption in certain sales; partition rights.)
What risks does the buyer assume? (Uncertainty of what will be received after partition; exposure to estate debts and adjustments; possible redemption.)

III. What can be sold, and how to describe it correctly

A. Sale of hereditary rights (share in the undivided estate)

This is the broadest form: the heir sells his “rights and interests” in the inheritance. The subject is the heir’s participation in the whole estate, not a particular asset.

Proper characterization:

“Sale/assignment of hereditary rights,” “sale of undivided hereditary share,” or “cession of hereditary rights.”

Practical effect:

The buyer steps into the heir’s shoes as to that share, and will eventually receive whatever is adjudicated to that share upon partition—after accounting for debts, expenses, legitimes, collation, and other adjustments.

B. Sale of an undivided share in a specific estate property

Sometimes an heir sells “my 1/6 share in the lot titled under the decedent,” while the estate remains undivided.

This can be valid as a sale of the heir’s ideal share in that particular property, but it still does not carve out a specific portion.

Important: Even if the deed points to a specific portion (“the eastern half” or “500 sqm portion”), that promise is generally inchoate until partition and may be ineffective to bind the others unless partition later awards that portion to the seller or the co-heirs consent to such segregation.

C. What cannot be sold (as a unilateral act)

A specific, determinate portion of a co-owned thing (e.g., “the kitchen,” “the second floor,” “the 100 sqm corner portion”) as if solely owned, without partition and without authority/consent of co-owners.
The entire co-owned property without authority from the other co-owners (unless the seller truly owns all shares).

A deed may still be “a sale,” but it will only be effective to the extent of the seller’s undivided share, not as a transfer of the whole.

IV. Capacity and timing: when the heir can sell

A. When hereditary rights arise

Hereditary rights arise from death, not from issuance of a title, not from estate tax payment, and not from settlement documents. Settlement documents and partition primarily declare and allocate, but the succession vests by operation of law.

Thus, an heir may sell his undivided share even before extrajudicial settlement or partition—again, subject to the rights of other heirs, creditors, and settlement requirements for enforceability against third persons.

B. During settlement proceedings

If there is a judicial settlement, estate properties may be under the control of the court/administrator for purposes of paying debts and distributing the remainder. The heir can still generally assign his hereditary share, but:

the assignment does not defeat estate administration,
the buyer takes subject to the court process,
and the heir cannot validly dispose of specific estate assets as if owner.

C. If the decedent left a will or if legitimes apply

The heir’s ability to sell is still there, but what the heir truly owns depends on:

the will’s dispositions,
compulsory heirs’ legitimes,
possible reductions of inofficious dispositions,
and other succession adjustments.

A buyer of hereditary rights assumes the risk that the seller’s eventual net share is smaller than expected.

V. Formal requirements and best practice documentation

A. Form of the conveyance

A sale of hereditary rights or an undivided share is a disposition of an interest in property; for enforceability and evidentiary strength, it should be in a public instrument (not merely private writing), especially when it affects real property.

Good drafting practice includes:

identifying the decedent, date of death, and relationship,
listing estate properties for reference but stating the sale is of “hereditary rights/undivided share,”
stating the seller’s share (e.g., “whatever share the seller is entitled to by law”),
clarifying that transfer is subject to estate obligations, partition, and legal redemption rights,
allocating who bears taxes and expenses,
warranties carefully limited (because the seller cannot warrant specific allocation),
special powers if the buyer will participate in partition.

B. Registration and annotation (real property)

A buyer will want protection against later transfers and to bind third persons. However, because what is acquired is an undivided share, registration practice can be tricky:

If the property is still titled solely in the decedent’s name, the usual sequence is:
1. settle/transfer title to heirs (extrajudicial settlement with deed of partition, or court decree), then
2. reflect the buyer’s acquisition from the heir (either by incorporating it into the settlement/partition, or by separate deed and annotation).

Still, parties often execute the deed of sale/assignment first, then later ensure it is recognized in the settlement instrument or court proceedings.

Practical note: A deed that cannot be registered immediately is not automatically invalid, but it may be vulnerable to conflicting transactions and disputes.

C. Estate tax and transfer considerations

In practice, transfer of title out of the decedent’s name typically requires estate compliance. Even if the heir sells earlier, the buyer must anticipate documentary requirements during settlement.

VI. Effects of the sale: what the buyer actually gets

A. The buyer becomes a co-owner (or successor to an heir’s place)

Depending on structure, the buyer becomes:

a co-owner of the estate (or of a particular property), to the extent of the purchased share; and/or
the holder of the seller’s rights to participate in partition and receive the seller’s eventual allotment.

The buyer’s rights include:

participation in partition (directly or through substituted rights, depending on documentation and acceptance by co-heirs/court),
entitlement to fruits/benefits proportionate to share after accounting,
and the ability to demand partition (subject to limitations).

B. The buyer does not get a specific property—yet

Until partition, the buyer generally cannot insist:

“Give me the house,” or
“I own the front half of the lot.”

What the buyer gets is the share—and later, the partition determines which assets satisfy that share.

C. The buyer takes subject to estate burdens and intra-heir adjustments

A buyer of hereditary rights takes the share as it exists, including the possibility of:

estate debts reducing the net distributable estate,
advancements/collation issues affecting the seller’s net share,
expenses of administration and settlement,
liens/encumbrances on estate assets,
disputes on heirship, legitimacy, preterition, or will validity,
and other legal reductions.

This is why buyers often discount the price or require protections (escrow, representations, indemnities).

VII. Limits on the seller’s power and consequences of overreaching

A. Selling more than one’s share

If an heir purports to sell:

the whole property, or
a determinate portion beyond what may be allotted to him,

the sale is generally effective only up to the seller’s undivided share (as a sale of his interest). The buyer cannot prejudice other co-owners.

B. Warranties and breach

If the deed is written as if conveying a specific property outright, problems arise when partition does not award that asset to the seller. Potential outcomes include:

reformation (treat as sale of undivided share only),
rescission or damages if there were misrepresentations and the buyer relied on them,
disputes over whether the contract was conditional on allocation.

Drafting should avoid promising allocation the seller cannot guarantee.

VIII. Rights of the other co-heirs: legal redemption and related protections

A. Co-ownership legal redemption (general rule)

Under co-ownership principles, when a co-owner sells his undivided share to a third person, the other co-owners are given a right of legal redemption—a statutory power to step into the buyer’s place by reimbursing the price (and in proper cases, associated expenses) within the period provided by law.

Core policy: Keep co-ownership from being disrupted by strangers and reduce friction among co-owners.

Key conditions typically involved:

There is a co-ownership;
A co-owner sells his undivided share;
Sale is to a third person (not another co-owner);
Redemption is exercised by a co-owner within the legally provided period (reckoned from notice in the manner recognized by law).

Practical implications:

A buyer who is not an heir/co-owner must anticipate that the purchase can be redeemed by the other heirs.
In many transactions, the buyer is either:
- another co-heir (to avoid redemption risk), or
- a family-affiliated buyer, or
- someone willing to price in the risk and require waiver/consent.

B. “Redemption among co-heirs” in hereditary rights context

When what is sold is hereditary rights, the same co-ownership redemption policy may arise because the heirs are co-owners of the undivided hereditary estate. The safer assumption in practice is that a transfer of an undivided hereditary share to a true outsider can be met with redemption by co-heirs, provided legal requisites are satisfied.

C. Waiver and notice issues

Co-heirs sometimes sign waivers/consents, but waivers should be approached carefully: they should be informed, specific, and properly documented to reduce later disputes.
The redemption period and the concept of notice can become highly contentious; parties should treat notice and documentation as essential.

IX. Partition: the central “endgame” of co-ownership

A. Right to demand partition

As a rule, no co-owner is obliged to remain in co-ownership. Any co-owner (including a buyer of an undivided share) can generally demand partition, unless:

partition is legally or physically impossible,
there is a valid agreement to keep the property undivided for a limited period (subject to legal limits),
or partition would defeat the purpose for which co-ownership was created (rare, fact-specific).

B. Types of partition

Voluntary (extrajudicial) partition among heirs (when allowed), documented through a deed.
Judicial partition when heirs cannot agree, or when court settlement is involved, or when there are disputes.

Partition may be:

partition in kind (physical division if feasible), or
partition by sale (property sold and proceeds divided) when division is impractical or would cause substantial impairment.

C. How the buyer’s interest is satisfied

After partition:

the buyer will receive the property/proceeds corresponding to the acquired share, but not necessarily a particular asset the buyer expected unless agreed and legally effected with all necessary parties.

X. Administration and use of the property while undivided

A. Possession and use

Each co-owner has a right to use the property in a manner consistent with its purpose, without excluding others. No co-owner may appropriate exclusive enjoyment beyond his share without accounting.

B. Fruits, income, rentals

Income (rentals, produce) is generally shared proportionately, subject to:

expenses,
necessary charges,
agreements on administration,
and accounting rules.

A buyer who acquires a share may be entitled to proportional fruits after acquisition, but must also share in charges.

C. Expenses and improvements

Necessary expenses and taxes are typically chargeable proportionately.
Useful improvements can raise reimbursement/credit issues depending on consent and benefit.
Luxury expenses are usually not reimbursable absent agreement.

These rules become relevant because buyers often enter a situation where one or more heirs have been in possession for years.

XI. Relationship to extrajudicial settlement of estate

A. Extrajudicial settlement prerequisites (practical environment)

Extrajudicial settlement is commonly used when:

the decedent left no will (or the will is not being probated in that process),
there are no outstanding debts (or they are settled),
and heirs are in agreement.

In that pathway, the typical deed combines:

settlement,
partition/allocation, and sometimes
simultaneous sale by one heir of his share to another heir or to a buyer.

B. Inclusion of the buyer in the deed

A common practical solution to enforce a share sale is:

the heir sells/assigns his hereditary rights to the buyer, and
the deed of extrajudicial settlement/partition either:
- recognizes the buyer as successor-in-interest, or
- allocates directly to the buyer the portion corresponding to the seller’s share.

This can reduce later registration friction.

XII. Interaction with family protections: legitimes and compulsory heirs

Even when a sale is valid, succession law constraints may affect what the seller truly had to sell:

Compulsory heirs’ legitimes restrict freedom of disposition and can affect the net shares.
If heirship is contested, or if a will changes distributions, the seller’s share might be reduced.
A buyer can end up with less than the deed’s stated fraction if that fraction assumed an incorrect heir count or incorrect legal entitlement.

For example, parties often assume equal shares among “children,” but later discover:

a surviving spouse changes the sharing,
there are additional heirs,
or there were prior marriages/legitimacy issues impacting proportions.

XIII. Common dispute patterns and how to structure around them

A. “He sold my inheritance”

Often what is really meant is:

the heir sold his undivided share, which is generally allowed; but
co-heirs object because they thought the property was being “taken away.”

Resolution often hinges on whether the deed purported to convey specific property or only the share, and on whether redemption is available/exercised.

B. “Buyer claims a specific portion”

Unless there is a valid partition (or unanimous agreement) awarding that portion, the buyer’s claim is usually limited to:

the seller’s undivided share, and
participation in partition.

C. “We didn’t consent to the sale”

Consent is not generally required for sale of an undivided share, but co-heirs may have:

redemption rights,
and may contest if the deed is being used to claim more than the seller’s share.

D. “Price was grossly low / heir was pressured”

This shifts into contract-law defenses (vitiated consent, fraud, undue influence) and may also raise ethical concerns when buyers prey on heirs needing cash. These are fact-intensive.

XIV. Due diligence checklist (for lawyers and parties)

For a buyer of an undivided inheritance share

Heirship verification
- Confirm the seller is truly an heir and the class of heirs is correctly identified.
Estate composition
- Inventory and verify ownership, titles, encumbrances.
Settlement status
- Is there a pending case? Is there an administrator? Any claims?
Debt and tax exposure
- Understand that debts reduce the net estate.
Co-heirs’ positions
- Expect resistance; plan for partition; assess redemption risk.
Drafting protections
- Clear description: sale of hereditary rights / undivided share only.
- Representations about heirship and authority.
- Indemnity for misrepresentation.
- Cooperation clause for settlement/partition.
- Escrow/holdback for contingencies.
Redemption risk management
- Obtain co-heirs’ waiver/consent where feasible; document notice strategy.

For an heir contemplating selling

Understand you are selling an ideal share, not a specific thing.
Be cautious of undervaluation; the buyer is pricing risk and leverage.
Keep the deed accurate to avoid later claims of fraud or overreach.
Coordinate with settlement/partition plans to avoid multi-year disputes.

XV. Practical drafting points: model clauses to include (conceptual)

Subject clause: “Seller sells, transfers, and assigns all his hereditary rights, interests, and participation in the estate of ___, deceased, to the extent of whatever share Seller is entitled to under law (or will), including rights to demand partition and receive adjudication.”
Non-specificity: “No specific property or determinate portion is hereby conveyed; allocation shall be determined upon settlement/partition.”
Assumption of risks: “Buyer acknowledges estate may be subject to debts, expenses, taxes, and legal adjustments affecting net share.”
Cooperation: “Seller shall cooperate in executing settlement/partition documents consistent with this assignment.”
Redemption disclosure: “Buyer is informed of possible legal redemption rights of co-owners/co-heirs in sales to third persons.”

XVI. Key takeaways

An heir may generally sell his undivided share in an inheritance even before partition, because what he owns is an ideal share that exists from the decedent’s death.
What is sold is a share, not a specific property—unless and until partition allocates.
The sale binds only the seller’s share and cannot prejudice the other co-heirs’ rights.
Co-heirs may have statutory redemption rights when a share is sold to a third person, creating a real risk to outside buyers.
The buyer inherits the uncertainties of succession: debts, taxes, legitimes, collation, disputes, and the outcome of partition.
Partition is the endgame; without it, ownership remains ideal and conflict-prone.
Good drafting and due diligence are essential because most disputes arise from deeds that pretend to convey specific assets or ignore redemption and settlement realities.