Adultery & Concubinage Case Procedures in the Philippines

A comprehensive practitioner-level guide

Disclaimer – This article is for academic and informational purposes only. It is not legal advice. Procedural nuances can change through new rules, jurisprudence, or local court practices; always consult qualified counsel for an actual case.

1. Statutory Foundations

Offense	Governing provision	Persons liable	Nature	Penalty¹
Adultery	Art. 333, Revised Penal Code (RPC)	Married woman and her paramour (who must know she is married)	Public crime but prosecuted only upon complaint of offended spouse	Prisión correccional in its medium and maximum periods (2 y-4 m & 1 d to 6 y)
Concubinage	Art. 334, RPC	Married man and his concubine	Same limitations on complaint	Husband: Prisión correccional in its minimum period (6 m & 1 d to 2 y-4 m); Concubine: destierro (banishment)

1 The RPC was amended by R.A. 10951 (2017) only with respect to value-based crimes; penalties for these “family honor” offenses remain unchanged.

2. Unique Elements of the Crimes

Adultery	Concubinage
1. Offender is a married woman. 2. She has sexual intercourse with a man not her husband. 3. Intercourse occurs during the marriage. 4. The paramour knows she is married.	1. Offender is a married man. 2. He (a) keeps a mistress in the conjugal dwelling, or (b) has sexual intercourse under scandalous circumstances, or (c) cohabits with his mistress in any other place. 3. Marriage still subsists.

Note the markedly different evidentiary burden: adultery requires proof of even a single act of intercourse; concubinage needs one of the three qualifying modes, all of which are harder to establish.

3. Quasi-Private Nature & Complaint Requirement

Who may file. Only the offended spouse may initiate prosecution (Art. 344, RPC).
Indispensable joinder. The complaint must include both guilty spouses/partners; omission of one bars prosecution of the other (People v. Cristobal, G.R. L-8665, 1956).
Form. A sworn Complaint-Affidavit is filed with the Office of the City/Provincial Prosecutor having venue.
Time bar (prescription). Both crimes prescribe in 10 years (Art. 90). The period is interrupted by filing the complaint.

4. Procedural Roadmap

Stage	Key Rules & Practical Notes
A. Preliminary Assessment	– Offended spouse gathers evidence (private investigator, digital messages, hotel receipts, photographs). – Counsel assesses sufficiency before public exposure—cases sometimes serve as leverage in civil settlement.
B. Filing of Sworn Complaint	– Venue: Prosecutor’s Office where any element occurred (usually place of intercourse or conjugal home). – Must attach marriage certificate, evidence of identity of paramour/concubine, and proof of alleged acts.
C. Inquest/Subpoena Investigation	– Because the penalty is above 4 years, regular preliminary investigation (Rule 112, Sec. 3, Rules of Criminal Procedure). – Respondents receive subpoenas; submit Counter-Affidavits and witnesses’ sworn statements.
D. Prosecutor’s Resolution & Information	– Possible outcomes: Dismissal, Filing of Information before trial court, or referral for additional evidence.
E. Warrant & Bail	– Adultery: bail mandatory (bailable as a matter of right). – Concubinage: same. – Typical bail range: ₱36,000–₱120,000 (subject to local bonds schedule).
F. Arraignment & Plea	– Held before the appropriate Municipal/Metropolitan Trial Court (MTC/MeTC) because the penalty does not exceed 6 years (Batas Pambansa 129, as amended). – Entering a mistaken guilty plea without counsel may later be withdrawn (constitutional right to counsel).
G. Pre-Trial	– Marking of documentary evidence, stipulation of facts, plea-bargain attempts (rare because no lesser offense exists).
H. Trial Proper	– Elements-based evidence presentation; prosecution must present intercourse (adultery) or qualifying mode (concubinage). – Testimony of spies/PI not barred (no marital privilege). – Digital evidence requires compliance with Rules on Electronic Evidence (A.M. 01-7-01-SC).
I. Judgment & Sentencing	– Conviction leads to imposition of penalties; accessory penalties include disqualification. – Courts rarely suspend sentence because the crimes are mala in se against family honor.
J. Post-Judgment	– Appeal to the RTC acting as appellate court (Rule 40) within 15 days. – Further appeal to CA and SC on pure questions.
K. Execution	– For destierro, court designates prohibited radius (25 km from offended spouse’s residence by convention).

5. Defenses & Mitigating Circumstances

Typical Defense	Basis
Absolution/Condonation	Prior express pardon of both offenders by offended spouse before institution (Art. 344, RPC); must be in writing or clearly proven.
Invalid marriage	Accused may show marriage void ab initio; no marital tie → no adultery/concubinage.
Widowhood/Annulment final	Criminal liability attaches only while marriage subsists.
Mistaken identity / lack of knowledge	Paramour unaware of woman’s marriage; concubine unaware husband married.
Alibi, frame-up, fabrication	As in any criminal case; subject to strict scrutiny.
Gestational or medical impossibility	Used to rebut inference of sexual intercourse (e.g., prolonged separation).

Extreme emotional stress or battered-spouse syndrome is not a statutory defense, but may mitigate penalty (Art. 13, RPC) or support a civil/criminal VAWC counter-case.

6. Evidentiary Issues

Corpus delicti for adultery: direct eyewitness testimony not indispensable; circumstantial evidence—frequent hotel check-ins, love letters, pregnancy—may suffice.
Scandal requirement in concubinage: publicity or flagrant nature must be shown if the second mode is charged.
Doctrine of res gestae: excited utterances of spouses sometimes admitted.
Marital & Privileged Communications: Art. III, Sec. 3(3), Constitution protects marital communications, but offended spouse is not prohibited from testifying.
Illegally obtained private communications: barred by Anti-Wiretapping Act & right to privacy; may be excluded.

7. Interplay with Civil & Administrative Remedies

Remedy	Relevance
Legal Separation (Art. 55, Family Code)	Adultery/Concubinage constitutes a ground; can be filed independently or after criminal conviction.
Annulment on Fraud or Psychological Incapacity	Criminal case evidence often feeds into these petitions.
Action for Moral & Exemplary Damages (Art. 26, Civil Code)	May be filed against guilty spouse/paramour separately; prescribes in 4 years from discovery (Art. 1146).
Violence Against Women & Children Act (R.A. 9262)	Emotional/psychological abuse arising from infidelity may be charged concurrently.
Administrative Sanctions	Public officials/ lawyers may face disciplinary cases for gross immorality.

8. Special & Contemporary Concerns

Gender disparity – Adultery punishes any intercourse of the wife; concubinage requires qualified circumstances for the husband → recurring constitutional challenge but upheld in Garcia v. Drilon (G.R. 179267, 2013) because Congress may protect marital fidelity differently.
Decriminalization Proposals – Senate Bills periodically filed to abolish these crimes as outdated; none passed as of April 2025.
Same-Sex Infidelity – Present statutes contemplate heterosexual relations; homosexual acts fall outside adultery/concubinage but may be processed under VAWC, psychological violence, or civil actions.
Digital Adultery – Sexting alone ≠ intercourse; must link to a physical act to sustain adultery charge, though it may prove lascivious intent.
OFW/Long-Distance Marriages – Venue hurdles; acts abroad require prosecution where the marriage was registered and at least one element occurred (often arrival photos in PH).
Plea Bargain to Acts of Lasciviousness – Occasionally allowed by prosecutors to spare family from scandal; requires offended spouse’s consent because still a private offense.

9. Flowchart Overview

Complaint (offended spouse)
        ↓
Prosecutor’s PI ← Pardon may still bar action
        ↓
Information filed in MTC
        ↓
Arraignment & Bail
        ↓
Pre-Trial
        ↓
Trial      ↩︎ Mediation/Settlement (rare)
        ↓
Judgment
        ↓
Appeals (RTC → CA → SC)

10. Practical Litigation Tips

For Prosecution Counsel

Secure documentary proof before confrontation; adultery evidence tends to disappear once suspects are alerted.
Draft the complaint to include specific dates and places; adultery covering a “period” is void for vagueness.
Anticipate pardon defense; attach evidence disproving consent—text threats, contemporaneous objections.

For Defense Counsel

Challenge venue and specificity of information.
Move to quash if required joinder absent or if complaint not personally signed by offended spouse.
Explore civil compromise; although criminal liability is public, offended spouse’s desistance often persuades prosecutor to dismiss for lack of interest.

11. Frequently Asked Procedural Questions

Question	Short Answer
Can the offended spouse testify to intercepted chats?	Only if obtained lawfully and not violating R.A. 4200.
May parties settle the criminal case?	Forgiveness before filing bars action; after filing it may lead to withdrawal but court may still proceed in theory though almost always dismisses.
Is pregnancy conclusive proof of adultery?	Presumption only; husband’s non-access must be shown (Art. 167, Family Code).
What if marriage is subsequently annulled?	Criminal liability that arose while the marriage existed remains.

12. Conclusion

Adultery and concubinage prosecutions occupy a complex niche between public justice and intensely private marital matters. The procedural landscape—anchored on the offended spouse’s complaint, the stringent joinder rule, and gender-skewed statutory definitions—demands meticulous evidentiary preparation and strategic timing. Whether invoked as leverage in marital negotiations or pursued to vindicate honor, these cases require counsel to navigate not just the Rules of Court but the intertwined threads of family law, privacy, and evolving social norms.

13. Key Authorities & Reading List (non-exhaustive)

Revised Penal Code, Arts. 333-335, 344, 345, 90-91
Rules of Criminal Procedure, Rules 112 & 120-124
Family Code of the Philippines, Arts. 26, 55
People v. Santos, 90 Phil 31 (1951) – Circumstantial evidence in adultery
People v. Zapata, G.R. L-45975 (1938) – Scandal requirement in concubinage
Garcia v. Drilon, G.R. 179267 (2013) – Gender-based scrutiny & VAWC interplay

Prepared April 30 2025, Manila, Philippines.