In the realm of Philippine labor law, the employment contract serves as the "law between the parties." However, even the most meticulously drafted documents can contain clerical slips, typographical errors, or mutual mistakes that do not reflect the true intention of the employer and the employee.

When a contract is already signed, correcting these errors requires adherence to specific legal principles to ensure the amendment is binding and does not inadvertently trigger a labor dispute.

1. The Principle of Reform of Instruments

Under the Civil Code of the Philippines, which applies supplementally to labor contracts, the primary remedy for a written contract that fails to express the true intent of the parties is Reformation.

Article 1359: When, there having been a meeting of the minds of the parties to a contract, their true intention is not expressed in the instrument purporting to embody the agreement, by reason of mistake, fraud, inequitable conduct or accident, one of the parties may ask for the reformation of the instrument to the end that such true intention may be expressed.

Requirements for Reformation:

There was a meeting of the minds (an agreement exists).
The written instrument does not express the true agreement.
The failure is due to mistake, fraud, inequitable conduct, or accident.

2. Common Methods of Correction

Depending on the gravity of the error and the stage of the employment relationship, parties typically use one of the following methods:

A. Addendum or Supplemental Agreement

This is the most professional and legally sound method for correcting significant errors (e.g., salary figures, job titles, or benefit clauses).

Process: A separate document is drafted titled "Addendum to the Employment Contract." It explicitly references the original contract date and specifies which clause is being modified.
Requirement: Both parties must sign the addendum.

B. "Pen-and-Ink" Corrections (Marginal Notes)

For minor typographical errors (e.g., a misspelled middle name or a wrong house number), parties often opt for manual corrections.

Process: Strike through the error, write the correction above it, and have both parties initial the change in the margin.
Risk: This is generally discouraged for substantive terms (like compensation) as it can be easily challenged as an unauthorized alteration.

C. Novation of Contract

If the errors are extensive, the parties may choose to supersede the old contract entirely.

Process: A new contract is executed, containing a "Superseding Clause" stating that this document replaces and renders void all previous agreements.

3. The Role of Mutual Consent

In Philippine Labor Law, the consent of the employee is paramount. Because the Constitution and the Labor Code lean toward the protection of labor, any unilateral change by the employer that results in the diminution of benefits is strictly prohibited.

Bilateral Correction: If both parties agree there was an error, the correction is straightforward.
Unilateral Correction: If an employer unilaterally "corrects" a contract to reduce a benefit (e.g., claiming a salary was a typo for ), it may be viewed as Constructive Dismissal or a violation of the Non-Diminution of Benefits rule.

4. Burden of Proof in Case of Dispute

If a case reaches the Labor Arbiter or the National Labor Relations Commission (NLRC), the party alleging the error bears the burden of proof.

Scenario	Legal Standing
Clear Clerical Error	If the error is obvious (e.g., "Year 20202" instead of "2022"), the courts usually favor the "True Intent" of the parties.
Substantive Dispute	If the employer claims a high commission rate was a "typo" but the employee claims it was an incentive, the doubt is usually resolved in favor of the employee (Art. 4, Labor Code).

5. Procedural Best Practices

To ensure that a correction is legally "bulletproof" in the Philippines, the following steps are recommended:

Written Notice: The party discovering the error should notify the other party in writing, explaining the nature of the mistake.
Formal Execution: Use an Addendum rather than manual erasures.
Notarization: While not strictly required for validity, notarizing the Addendum or the new contract makes it a public document, providing stronger evidentiary weight in court.
Copy Distribution: Ensure the employee receives an original, signed, and/or notarized copy of the corrected document.

Summary Table: Correction Methods

Method	Best Used For	Legal Complexity
Initialed Change	Typos, dates, spelling.	Low (but risky)
Addendum	Salary, benefits, job scope.	Medium (Standard)
New Contract	Multiple errors or structural changes.	High (Comprehensive)