Introduction

In the Philippines, adultery remains a criminal offense under the Revised Penal Code (RPC), specifically governed by Article 333. This provision defines adultery as a crime committed by a married woman who engages in sexual intercourse with a man who is not her husband, as well as by the man who has carnal knowledge of her, knowing that she is married. The offense is distinct from concubinage, which applies to married men under Article 334 and involves different elements, such as keeping a mistress in the conjugal dwelling or cohabiting scandalously elsewhere. Adultery cases are pursued through the criminal justice system rather than civil courts, emphasizing their status as public crimes that affect societal morals and family integrity.

The filing and prosecution of adultery cases are influenced by Republic Act No. 9262 (Anti-Violence Against Women and Their Children Act of 2004), which provides additional protections for women but does not decriminalize adultery. However, cultural and societal shifts have led to fewer prosecutions in recent years, with many cases settled privately or through alternative dispute resolutions. Despite this, the legal framework persists, and aggrieved spouses—typically husbands—may still pursue charges. This article comprehensively outlines the process for filing such cases, associated legal fees, potential defenses, penalties, and related considerations within the Philippine legal context.

Legal Basis and Elements of Adultery

Under Article 333 of the RPC, the essential elements of adultery are:

The woman is married.
She engages in sexual intercourse with a man not her husband.
The man knows of her marital status.

Proof of these elements requires substantial evidence, such as eyewitness testimonies, admissions, photographs, messages, or forensic evidence like DNA tests. Mere suspicion or circumstantial evidence may not suffice for conviction, as the standard is proof beyond reasonable doubt. The crime is considered consummated upon the act of sexual intercourse, and each instance constitutes a separate offense.

Adultery is a private crime, meaning it can only be initiated by the offended spouse (the husband in adultery cases). If the offended spouse consents to or pardons the act, the case cannot proceed (Article 344, RPC). Pardon can be express or implied, such as through continued cohabitation after knowledge of the infidelity. Additionally, if both spouses are guilty of adultery or concubinage, neither can prosecute the other.

In cases involving overseas Filipino workers (OFWs) or separations, jurisdiction falls under Philippine courts if the marriage was solemnized under Philippine law, per the nationality principle in criminal law (Article 2, RPC).

Process for Filing an Adultery Case

Filing an adultery case follows the standard criminal procedure in the Philippines, as outlined in the Rules of Court and the Revised Rules on Criminal Procedure (as amended). The process is initiated at the prosecutorial level and may escalate to trial if probable cause is found. Below is a step-by-step breakdown:

1. Pre-Filing Preparation

Gather Evidence: Collect affidavits, witness statements, electronic evidence (e.g., text messages, emails, or social media posts compliant with Republic Act No. 10175, the Cybercrime Prevention Act), hotel records, or medical reports. Electronic evidence must be authenticated to be admissible.
Consult a Lawyer: Engage a private attorney specializing in family or criminal law. Public Attorneys' Office (PAO) assistance may be available for indigent complainants.
Verify Marital Status: Ensure proof of marriage (e.g., marriage certificate from the Philippine Statistics Authority).

2. Filing the Complaint

Where to File: Submit a sworn complaint-affidavit to the Office of the City or Provincial Prosecutor in the jurisdiction where the crime was committed (Rule 110, Section 3, Rules of Court). If the act occurred in multiple places, filing can be in any relevant jurisdiction.
Contents of the Complaint: Include details of the offense, identities of the accused (the wife and her paramour), evidence, and the complainant's sworn statement. The complaint must be subscribed before a prosecutor or notary public.
Filing Fee: There is no filing fee for criminal complaints at the prosecutor's office, as these are government-initiated proceedings. However, nominal costs for photocopying and notarization may apply (typically PHP 100–500).

3. Preliminary Investigation

Conduct by Prosecutor: The prosecutor reviews the complaint and may require the respondent (accused) to submit a counter-affidavit within 10 days. Rejoinder affidavits may follow.
Resolution: If probable cause exists, the prosecutor files an information with the Municipal Trial Court (MTC) or Regional Trial Court (RTC), depending on the penalty. Adultery carries a penalty of prisión correccional (2 years, 4 months, and 1 day to 6 years), placing it under RTC jurisdiction (Batas Pambansa Blg. 129, as amended).
Duration: This phase typically takes 1–3 months but can extend due to backlogs.
Costs: No official fees, but transportation and document preparation may cost PHP 1,000–5,000.

4. Arraignment and Pre-Trial

Arraignment: The accused enters a plea (guilty or not guilty) before the court.
Pre-Trial Conference: Parties discuss stipulations, evidence marking, and possible plea bargaining. Under Republic Act No. 11576, plea bargaining for adultery may reduce penalties or lead to probation.
Bail: Adultery is bailable. Bail bond amounts range from PHP 24,000–36,000, depending on the court and circumstances (based on Department of Justice bail guidelines).

5. Trial Proper

Presentation of Evidence: Prosecution presents witnesses and evidence first, followed by the defense. Cross-examinations occur.
Duration: Trials can last 6 months to 2 years or more, influenced by court schedules and complexities.
Judgment: If convicted, sentencing follows. Appeals can be filed with the Court of Appeals and Supreme Court.

6. Post-Trial and Execution

Execution of Judgment: If final, the convict serves the sentence or pays fines (though adultery primarily involves imprisonment).
Civil Aspects: A criminal conviction can support annulment or legal separation under the Family Code (Articles 45 and 55), potentially leading to custody, support, and property disputes.

Estimated Legal Fees

Legal fees for adultery cases vary based on location (e.g., Metro Manila vs. provinces), case complexity, lawyer experience, and duration. Estimates are based on standard practices and Bar guidelines (Integrated Bar of the Philippines rates). All figures are in Philippine Pesos (PHP) and approximate as of current economic conditions.

1. Attorney's Fees

Acceptance Fee: PHP 50,000–150,000 upfront for handling the case from filing to trial. For high-profile lawyers in urban areas, this can reach PHP 200,000+.
Appearance Fees: PHP 5,000–10,000 per hearing. With 10–20 hearings, this adds PHP 50,000–200,000.
Success Fee: 10–20% of any civil damages awarded if bundled with a related civil suit (e.g., for moral damages under Article 2219, Civil Code).
PAO or Free Legal Aid: Free for qualified indigents (income below PHP 14,000/month per family member in Metro Manila).

2. Court-Related Fees

Docket Fees: For the criminal information, minimal or none, as it's a public prosecution. If civil damages are claimed (via reservation under Rule 111), docket fees apply: 1% of claimed amount (e.g., PHP 10,000 for PHP 1,000,000 in damages).
Bail Bond Premium: 1–2% of bail amount (e.g., PHP 240–720 for PHP 24,000 bail).
Transcript and Certification Fees: PHP 20–50 per page for court records.
Sheriff's Fees: PHP 1,000–5,000 for service of summons and subpoenas.

3. Miscellaneous Expenses

Evidence Gathering: Private investigator fees (PHP 20,000–100,000), forensic tests (PHP 5,000–50,000 for DNA or digital forensics).
Travel and Logistics: PHP 5,000–20,000 for out-of-town cases.
Notarization and Documentation: PHP 500–2,000.
Expert Witnesses: PHP 10,000–50,000 per appearance (e.g., psychologists for impact on children).

Total Estimated Cost

Low-End (Simple Case, Provincial Court): PHP 50,000–100,000 (excluding bail).
Mid-Range (Urban, Contested): PHP 150,000–300,000.
High-End (Complex, Appeals): PHP 500,000+. These costs can be mitigated through settlements or alternative resolutions, such as mediation under the Katarungang Pambarangay (for non-serious crimes, though adultery's gravity may exclude it).

Penalties and Defenses

Penalties

Imprisonment: Prisión correccional in its medium and maximum periods (2 years, 4 months, 1 day to 6 years) for both the wife and paramour.
Destierro: Possible for the paramour if acquitted but deemed a threat.
Civil Liabilities: Restitution, moral damages (PHP 100,000–500,000), and exemplary damages.

Common Defenses

Lack of proof of marriage or knowledge thereof.
Pardon or consent by the offended spouse.
Prescription: Action prescribes in 15 years (Article 90, RPC).
Insanity or other exempting circumstances (Article 12, RPC).
Challenges to evidence admissibility, especially electronic under the Rules on Electronic Evidence.

Related Considerations

Adultery prosecutions can intersect with other laws:

Family Code: Grounds for legal separation or annulment.
RA 9262: If violence is involved, it may shift focus to abuse charges.
Cybercrime Law: For evidence obtained online.
Data Privacy Act (RA 10173): Ensures evidence collection respects privacy. Social stigma, emotional toll, and impact on children often deter filings. Recent legislative proposals aim to decriminalize adultery, aligning with global trends, but as of now, it remains enforceable.

In summary, pursuing an adultery case demands careful evidence preparation, significant financial commitment, and awareness of procedural intricacies. Aggrieved parties should weigh legal recourse against personal and familial consequences.