In Philippine real estate and estate settlement, it is not uncommon for families to discover an old, unrecorded Deed of Absolute Sale tucked away in an ancestor’s trunk. Often executed decades ago, these documents are vital links in establishing ownership over unregistered land or transferring titles under the Torrens system.

However, when an old Deed of Sale suddenly surfaces, it frequently invites skepticism. Heirs of the seller may claim the signature was forged, or the Register of Deeds may flag the signature due to discrepancies with current identification documents.

Verifying the authenticity of a signature on an old Deed of Sale involves a complex interplay of Philippine civil law, the rules of evidence, and forensic science.

1. The Legal Weight of a Notarized Deed of Sale

Under Philippine law, a Deed of Sale that has been acknowledged before a Notary Public is classified as a public document.

According to Rule 132, Section 23 of the Revised Rules on Evidence, public documents are evidence of the facts stated therein without need for further proof of their execution. A notarized document enjoys the presumption of regularity.

The Legal Burden: To overthrow the presumption of regularity of a notarized Deed of Sale, the party alleging forgery must present evidence that is clear, convincing, and more than merely preponderant. A mere denial by the alleged signer or their heirs is insufficient to invalidate the document.

2. How Signatures Are Verified Under the Rules of Court

When the authenticity of a signature on an old deed is challenged in court, the party asserting forgery or seeking to prove authenticity cannot rely on speculation. Rule 132, Section 22 of the Revised Rules on Evidence explicitly dictates how the handwriting or signature of a person may be proven:

By a Witness Who Saw the Execution: A witness who actually saw the person sign the document can testify to its authenticity.
By a Witness Familiar with the Handwriting: A witness who has a lawful familiarity with the person’s handwriting (e.g., a family member, long-time business partner, or employee who has seen them write or received correspondence from them) can testify that they recognize the signature.
By Comparison: The court itself, or an expert witness, can compare the questioned signature with specimens admitted or treated as genuine by the party against whom the evidence is offered, or proved to be genuine to the satisfaction of the judge.

3. The Role of Forensic Document Examination (NBI and PNP)

When visual inspection by the parties is insufficient, courts rely on forensic expert witnesses, typically from the National Bureau of Investigation (NBI) or the Philippine National Police (PNP) Questioned Documents Division.

Forensic document examiners analyze handwriting characteristics that are nearly impossible to replicate perfectly, such as:

Stroke direction and sequence
Pen pressure and shading
Line quality and tremor (which can distinguish a natural signature from a slowly traced forgery)
Slant, spacing, and alignment

The Challenge of "Contemporaneous" Specimens

To verify an old signature, the expert requires standard or specimen signatures written around the same time the deed was executed.

Human handwriting changes naturally over time due to age, physical health, psychological state, and profession. For example, if a Deed of Sale was executed in 1975, comparing it to a signature from 2010 is legally and scientifically weak. The examiner will require other documents from the mid-1970s (e.g., old voter’s IDs, marriage contracts, bank logs, or old letters) to establish an accurate baseline.

4. The Supreme Court Doctrine on "Variance"

A common misconception is that any physical difference between two signatures automatically proves forgery. The Philippine Supreme Court has repeatedly ruled that variance alone does not mean forgery.

In numerous jurisdictions, the high court has noted that the passage of time, illness, stress, or even the writing instrument and surface used can cause variations in a person's signature. A person’s signature is fluid, not a mechanical stamp. Therefore, minor differences between an old deed's signature and standard specimens do not instantly nullify the document; the discrepancies must show a total divergence in writing habits and characteristics.

5. Prescription and Laches: Can It Be Too Late to Question a Signature?

If a signature on a Deed of Sale was indeed forged, the contract is considered void ab initio (void from the beginning) because there was a total lack of consent.

Prescription: Under Article 1410 of the Civil Code of the Philippines, "The action or defense for the declaration of the inexistence of a contract does not prescribe." This means that, theoretically, you can challenge a forged deed regardless of how many decades have passed.
Laches (Stale Claims): While the action does not prescribe, it can be barred by laches. Laches is the failure or neglect, for an unreasonable and unexplained length of time, to do that which, by exercising due diligence, could or should have been done earlier. If the heirs knew about the old Deed of Sale and allowed the buyer to openly, continuously, and peacefully occupy the land for 30 or 40 years without protest, courts may deny the claim of forgery based on equity and the stabilization of property rights.

Summary of Actionable Steps for Verification

Scenario	Recommended Legal & Practical Steps
You want to prove the deed is genuine	1. Secure the Notarial Register from the National Archives of the Philippines (if the notary's records were turned over).

2. Gather contemporaneous public documents (marriage contracts, older titles) signed by the seller.

3. Locate the surviving instrumental witnesses listed on the deed. | | You suspect the deed is forged | 1. File a petition for the Declaration of Nullity of the Deed of Sale.

2. Request a subpoena for the original document from the custodian.

3. Engage the NBI or PNP Questioned Documents Division to conduct a formal handwriting analysis using verified specimen signatures from the same era. |