In the Philippines, the death of a decedent triggers the immediate transmission of the estate to the heirs. Under Article 777 of the Civil Code, "the rights to the succession are transmitted from the moment of the death of the decedent." However, until a formal partition occurs, the heirs exist in a state of co-ownership.

Problems frequently arise when one co-heir, through deceit, forgery, or unauthorized representation, transfers a portion of the estate—or the entirety of it—to themselves or a third party without the consent of the other heirs.

1. The Nature of the Legal Infringement

When a co-heir disposes of a specific property belonging to the undivided estate, the sale is not necessarily void in its entirety, but its effect is limited. Under the law on co-ownership (Article 493, Civil Code), a co-owner has full ownership of his part and the fruits thereof, but the effect of the alienation is limited to the portion which may be allotted to him in the division upon the termination of the co-ownership.

However, if the transfer was predicated on a falsified Affidavit of Self-Adjudication or a forged Deed of Extrajudicial Settlement, the transfer is fraudulent and subject to specific legal challenges.

2. Civil Remedies

A. Action for Annulment of Title and Reconveyance

This is the primary remedy. If a co-heir successfully registers the property in their name through fraud (e.g., by claiming they are the sole heir), the aggrieved heirs can file an action for Reconveyance.

Ground: The property is still deemed held in an implied trust for the benefit of the true heirs (Article 1456, Civil Code).
Prescription: * If based on fraud: Four (4) years from the discovery of the fraud.
If based on an implied/constructive trust: Ten (10) years from the date of the issuance of the Certificate of Title.
If the plaintiff is in possession: The action is imprescriptible.

B. Judicial Partition (Rule 74, Section 1)

If the heirs cannot agree on how to divide the estate, or if one heir denies the existence of the co-ownership, any heir may file a complaint for Judicial Partition. In this proceeding, the court will first determine if a co-ownership exists and then oversee the equitable distribution of the properties.

C. Cancellation of Title and Damages

If the property has been transferred to a third party, the success of this remedy depends on whether the buyer was a purchaser in good faith and for value.

If the buyer knew of the other heirs, the title can be cancelled.
If the buyer is innocent, the aggrieved heirs may instead sue the fraudulent co-heir for damages.

3. Criminal Remedies

A co-heir who fraudulently transfers property may be held criminally liable under the Revised Penal Code (RPC):

Estafa (Article 315): If the co-heir used deceit or false pretenses to deprive others of their share.
Falsification of Public Documents (Article 171/172): Applicable if the co-heir forged signatures on a Deed of Sale or executed a false Affidavit of Self-Adjudication (claiming they are the "sole heir" when they are not).
Perjury: If the co-heir willfully and knowingly made untruthful statements under oath in a public document.

4. Administrative Remedies

Adverse Claim

To prevent the further transfer of the property while a court case is pending, an aggrieved heir should file a Notice of Adverse Claim with the Register of Deeds. This serves as a warning to the whole world that there is a dispute regarding the ownership of the property.

Notice of Lis Pendens

Once a civil case for reconveyance or partition is filed, the heir should record a Notice of Lis Pendens ("suit pending") on the title. This ensures that anyone who acquires an interest in the property does so subject to the outcome of the litigation.

5. Key Jurisprudential Principles

The "Sole Heir" Fallacy: The Supreme Court has repeatedly ruled (e.g., in Tan vs. Benolirao) that an Extrajudicial Settlement is not binding upon heirs who did not participate in it or had no knowledge of it. As to them, the settlement is void.

Prescription among Co-heirs: Generally, prescription does not run against a co-heir as long as they expressly or impliedly recognize the co-ownership. However, if a co-heir repudiates the co-ownership (usually by getting a new title and expressing exclusive ownership), the prescriptive period begins to run.

Summary Table of Remedies

Remedy	Objective	Prescriptive Period
Reconveyance	To recover the title to the property	10 years (Implied Trust)
Judicial Partition	To force the legal division of the estate	Imprescriptible (generally)
Criminal Complaint	To penalize the fraud/forgery	Varies (usually 10–15 years)
Annulment of Sale	To void the transfer to a third party	4 years from discovery
Adverse Claim	To freeze the title and prevent sale	30 days (effective duration)