Bigamy in Ningbo is not only invalid marriage, but also may constitute bigamy.

Once the extramarital affair comes to the step of "in the name of husband and wife", the nature will change completely. Many people believe that, at worst, a bigamous marriage is simply “not legally recognized”; others think that as long as a second marriage certificate has not been obtained, it will never constitute a crime. Neither of these interpretations is accurate.Under China’s current legal system, bigamy is an act that entails both civil and criminal liability.: In civil law, bigamy is a statutory ground for invalidating a marriage, and the party without fault may also claim damages in a divorce proceeding. In criminal law, bigamy constitutes the crime of bigamy under Article 258 of the Criminal Law and is punishable by imprisonment of up to two years or by detention. In other words, bigamy is not merely a matter of “marriage being void”; the perpetrator may also be held criminally liable. Below, we will clearly explain the criteria for determining bigamy, its civil and criminal consequences, the avenues for holding perpetrators accountable, and key points for gathering evidence, along with practical contact channels specific to the Ningbo area.

1. what counts as "bigamy" in law"

The criterion for determining bigamy does not hinge on the depth of emotional attachment or the duration of cohabitation, but rather on whether “two relationships simultaneously exist that are legally recognized as marriages.” Article 258 of the Criminal Law defines it as two scenarios: “a person who has a spouse and enters into another marriage, or a person who marries another knowing that the other party is already married.” In judicial practice, bigamy primarily takes the following forms.

(I) Legal marriage + legal marriage: two registered marriages

This is the most typical and easiest-to-identify form of bigamy. A person who is already married registers for marriage with another person at the civil affairs bureau without first having their previous marriage legally dissolved. In the past, marriage registration data was not yet interconnected nationwide, which some people exploited to obtain another marriage certificate in a different locality. Today, the information is largely networked, but instances of bigamy stemming from historical records still persist. Evidence of such bigamy is best preserved in a fixed form—two marriage certificates and two sets of marriage registration records constitute irrefutable written proof of bigamy.

(II) Legal marriage + de facto marriage: after registration, they live together as husband and wife.

Even if the perpetrator has already registered the marriage and subsequently fails to re-register, cohabiting with a person of the opposite sex outside the marriage under the guise of a marital relationship may still constitute bigamy. The "de facto marriage" here is not random cohabitation, but requires the degree of "living together in the name of husband and wife. The Supreme People’s Court has explicitly stated in relevant replies and historical judicial views that a person who is married and cohabits with another person under the guise of marriage, or who knowingly cohabits with a person who is already married under the guise of marriage, shall be treated as having committed bigamy.

How to judge "in the name of husband and wife"? Usually, we can see these external manifestations: matching husband and wife externally; holding weddings and banquets for relatives and friends; taking wedding photos and honeymoon trips together; signing documents, purchasing real estate and handling loans together in the name of husband and wife; having children and registering and informing them as husband and wife; neighbors and colleagues generally think that they are husband and wife. There must be both objective and subjective manifestations of “cohabiting as husband and wife,” and the relationship must also be “widely known” within a certain scope. A court has explicitly held that where both parties have separate residences and are not publicly recognized as a married couple by an indefinite majority of people in public, such a situation does not constitute bigamy.

(III) Cohabitation and extramarital affairs alone generally do not constitute bigamy.

Clarification is needed: Generally, extramarital affairs, long-term cohabitation, and maintaining a mistress or lover do not constitute bigamy, nor do they amount to the crime of bigamy, as long as no second marriage registration has been filed and no “cohabitation under the guise of a married couple” has taken place. Taking a few intimate photos and cohabiting for an extended period while publicly presenting oneself merely as “boyfriend and girlfriend” constitutes a fault on the moral and civil levels, but does not amount to bigamy under criminal law. The primary consequences are entitlement to divorce damages and an unfavorable assessment in the division of marital property. Furthermore, the legal validity of de facto marriage is subject to a time limit: de facto marriages existing prior to February 1, 1994—when the Regulations on the Administration of Marriage Registration came into effect—are recognized by law, whereas those occurring thereafter are treated solely as cohabitation. Consequently, when determining whether bigamy has occurred, one must first ascertain whether the “first” marriage was lawful and valid.

2. Civil consequences of bigamy: invalidity of the marriage, damages, and property division.

(I) Bigamy is a statutory ground for the invalidity of marriage.

Article 1,051 of the Civil Code stipulates: "A marriage is invalid if any of the following circumstances exists: (I) bigamy; (II) a prohibited kinship relationship; (III) failure to reach theLegal marriage age." Bigamy is listed as the first ground for invalidity. A marriage that has been declared invalid on the grounds of bigamy has no legal effect from the outset, and the parties do not have the rights and obligations of spouses. Case

concerning the dispute over the invalidity of the marriage between Gao and Zhu can serve as an illustration. While his marriage to his former wife was still legally valid, Zhu concealed the fact that he was already married from Gao, entered into another registered marriage with her, and had children with her; it was only many years later that Gao learned her husband had been married all along. The court held that, during the subsistence of his previous marriage, Zhu entered into another registered marriage with another person, thereby violating the principle of monogamy and constituting bigamy. Consequently, his marriage with Gao is void ab initio and not protected by law. This reminds us that the party harmed by bigamy is often also the one who has been deceived, and even without knowledge of the facts, they may nonetheless find themselves in an invalid marriage.

It is also necessary to distinguish between “invalidity” and “voidability”: bigamy constitutes a ground for the invalidity of a marriage, not its voidability; in addition to the parties themselves, interested parties may also apply for a declaration of the marriage’s invalidity, and those who bring such an application on the ground of bigamy may include the parties’ close relatives as well as grassroots organizations.

(II) The party at no fault may claim divorce damages.

Article 1091 of the Civil Code stipulates that if divorce is caused by bigamy, cohabitation with others, domestic violence, maltreatment and abandonment of family members or other serious faults, the party without fault has the right to claim damages. In other words, bigamy not only renders the second marriage invalid but also confers on the innocent party in the original marriage a right to claim damages, which may encompass both material and emotional harm.

There are several procedural rules when it is exercised: if the innocent party acts as the plaintiff to sue for divorce, it should generally be brought together in the divorce proceedings; if the defendant does not agree to divorce and does not offer compensation, he can sue separately; if he sues on the grounds of this article after divorce by agreement, the court should accept it, except for those that have been explicitly abandoned in the agreement. If both parties are at fault, the court will not support either party’s claim for compensation. Bigamy is also a statutory ground for determining that the marital relationship has indeed broken down and for granting a divorce when mediation has failed.

(III) How should the property involved in bigamy be handled?

Article 1,054 of the Civil Code provides that a void marriage has no legal binding force from the outset; property acquired during the cohabitation period shall be disposed of by agreement between the parties; if no agreement is reached, the court shall make a judgment in accordance with the principle of protecting the faultless party.In the property division arising from a void marriage due to bigamy, the property rights of the parties to a lawful marriage shall not be infringed.; The provisions concerning parents and children shall apply to the children born thereof. In practice, the lawful spouse may participate in litigation concerning the division of property in an invalid marriage involving bigamy as a third party with an independent claim.

Is a gift of jointly owned property made by one spouse to a third-party romantic partner without the other spouse’s consent valid? In the case of “Zhang Anan v. Xiaoyue,” the husband transferred four million yuan of marital assets to his mistress under the guise of an “investment advisory agreement,” and the wife filed a lawsuit seeking its return. The court determined that no genuine advisory relationship existed between the parties; the contract was, in essence, a legally permissible form concealing the purpose of making payments to a lover. As the gift infringed upon the rights and interests of the spouse, the court ordered the lover to return the funds. It is evident that, when confronted with the outflow of marital assets, the original spouse is not merely relegated to passively accepting the situation.

3. Criminal consequences of bigamy: Article 258 of the Criminal Law

(I) Charges and Penalties

Article 258 of the Criminal Law, on the crime of bigamy, stipulates: “Anyone who commits bigamy while having a spouse, or who marries another person knowing that the other party is already married, shall be sentenced to imprisonment of no more than two years or to criminal detention.” The object of infringement in the crime of bigamy is the monogamous marriage system, and the subjective element requires direct intent.

(II) Two categories of criminal subjects

There are two categories of subjects who may commit the crime of bigamy. The first category comprises individuals who are already married but remarry—meaning they have a legally recognized spouse and subsequently marry another person or cohabitate with someone else as husband and wife. The second category comprises individuals who “knowingly marry someone who is already married”; that is, although they themselves are unmarried, they knowingly enter into a registered marriage with or cohabitate with the other party as husband and wife, despite being aware that the other party is already married. In other words, a “third party” who interferes in another person’s marriage may also be held liable as a perpetrator of the crime of bigamy, provided that they acted with knowledge and entered into a marriage (including a de facto marriage) with the married individual; it is not only the adulterous party who can be held accountable.

(III) How is "knowing" determined?

The crime of bigamy does not punish everyone who has a relationship with a married person; the key issue is whether they “knew” about the other party’s marital status. "Knowing" is a subjective element, which needs to be judged by objective facts presumption. Common bases include: the length of time the two parties have communicated and whether they know the family situation of the other party; Whether the other party has shown a divorce certificate; Whether the marriage registration has been handled (registration is often directly presumed to be knowable); Whether the people around you have told the other party that they are married; Whether the chat records and transfer notes reflect the knowledge of the fact of marriage, etc. If one is genuinely unaware that the other party is married—such as when they have been deliberately misled and deceived—and therefore lacks knowledge of the fact, they generally do not constitute the crime of bigamy. In such cases, it is usually only the married party who is held accountable, while the deceived party is, in effect, the victim.

4. Who will prosecute and how: private prosecution and public prosecution

(I) bigamy cases can be prosecuted by private prosecution or public prosecution

The crime of bigamy is not a “complaint-based” offense. According to the Criminal Procedure Law and its judicial interpretations, bigamy cases do not fall under the category of offenses that are prosecuted only upon complaint; rather, they are classified as “minor criminal cases for which the People’s Procuratorate has not instituted public prosecution and in which the victim possesses evidence.” This means a case of bigamy.It may be prosecuted by the victim through a private prosecution in court, or it may be investigated by the public security organs and prosecuted by the procuratorial organ.. Bigamy directly infringes upon the interests of the other party in a lawful marriage; moreover, such conduct is often concealed and difficult to detect on its own. Allowing the victim to file a complaint independently can broaden the avenues for holding perpetrators accountable.

In practice, there are generally two main approaches. First, private prosecution: If the victim possesses relatively solid evidence, they may directly file a criminal private prosecution with the competent court, which shall accept the case in accordance with the law. Second, pursue the public security and procuratorial procedures: file a report with the public security organ, which will initiate an investigation, transfer the case to the procuratorate for review and prosecution, and then institute public prosecution. Furthermore, in the course of hearing civil cases such as divorce, if the court finds that a party is suspected of bigamy and the victim does not file a private prosecution, the case shall be referred to the public security organ for handling as a public prosecution case.

(II) What evidence is required to establish bigamy?

Whether it is a private prosecution or a public prosecution, the core issue is to prove either “cohabitation under the guise of marriage” or “second registration of marriage.” Common evidence includes:

• Marriage registration records: the two marriage certificates—one issued before and one after—and the marriage registration file along with the inquiry results constitute direct evidence of “legal marriage followed by another legal marriage.”
• Evidence of cohabitation as husband and wife: wedding photos and videos, engagement or wedding portraits, contracts or property jointly registered in both names, records of jointly renting or purchasing a home, forms filled out using “husband and wife” status, records of jointly having and raising children, etc.
• Witness statements from the public: Testimonies from neighbors, colleagues, relatives and friends, property management, and the community confirming that the two have long referred to each other as husband and wife and have been publicly recognized as a married couple.
• Information regarding the birth of children—such as the birth certificate, household registration records, and paternity test results—often reflects the couple’s cohabitation as a married couple.
• Other supporting evidence: chat records, transfer records, call logs, travel records, photos and videos of cohabitation, etc.

It needs to be emphasized that the identification of bigamy requires "in the name of husband and wife" and is "well known" within a certain range. Only a few times of opening a house and short-term cohabitation usually fail to meet the proof standard. This is also the reason why many parties are "clear in their hearts" but difficult to pursue responsibility due to insufficient evidence.

Key Points and Risks of 5. Evidence: The Boundary of Legal Evidence

Evidence of bigamy is often concealed within the confines of family life; gathering such evidence must be both effective and lawful. The most important bottom line is:Evidence obtained by seriously infringing upon the lawful rights and interests of others, violating prohibitive provisions of the law, or gravely contravening public order and good morals shall not be admissible as the basis for establishing facts.。

Specifically, it is permissible to lawfully collect photographs and videos taken in public places, surveillance footage of joint outings, and records of purchases, as well as any materials already in one’s possession. As for chat logs and transaction records, they may be preserved by securing the original devices or, where necessary, by applying for evidence preservation or notarization. However, one must avoid unauthorized entry into another person’s residence to secretly install devices, illegally obtain the content of others’ communications, unlawfully access others’ private information, or use threats or coercion to extract evidence—actions that not only may result in the exclusion of such evidence but could also subject the evidence‑gatherer to liability for torts, as well as administrative or criminal penalties.

Legitimate avenues for gathering evidence typically include: obtaining (or requesting the court to obtain) marriage registration records from the marriage registry; securing, through public channels, evidence of the other party’s conduct in the capacity of a spouse; and, on a voluntary basis, obtaining the other party’s written admission or undertaking. When necessary, one may apply to the court for investigation and evidence collection through litigation; this approach is often more reliable.

6. Common defenses and their boundaries

(I) "I didn't know the other person was already married."This is the most common defense raised by the third party. “Knowing” is a subjective element of the crime of bigamy; if one genuinely does not know that the other party is already married and has been misled or deceived by them, it generally does not constitute the crime of bigamy. However, whether such a defense can succeed depends on the objective evidence: if the parties have maintained a long-term relationship, the other party’s family circumstances are publicly known, and third parties have repeatedly informed the defendant, or if they have even jointly completed registration procedures, “lack of knowledge” is often difficult to establish.

(II) "We are just living together; we haven't registered our marriage."This depends on whether the cohabitation has reached the level of “living together as husband and wife.” If the relationship is merely cohabitation outside of marriage, with neither party presenting themselves as spouses to others, it generally does not constitute bigamy and only entails civil liability for “cohabiting with another person.” However, if the parties present themselves as husband and wife to the public and are recognized by those around them as such, even without a second marriage registration, it may still constitute bigamy under the doctrine of de facto marriage.

(III) "We're already divorced, we just haven't gone through the formalities." This is a typical pretext for bigamy, which is legally untenable. The marriage relationship must be dissolved in accordance with the procedure-the divorce in litigation shall be subject to the effective judgment or mediation agreement, and the divorce by agreement shall be registered with the marriage registration authority. Only signing a "divorce agreement" and oral agreement to separate will not have the effect of dissolution. In the case of Gao and Zhu, Zhu argued that he had "signed a divorce agreement" with his ex-wife, but because he had not registered for divorce, the court found that his previous marriage still existed and bigamy was established.

There is also a technical problem: if the bigamy situation has disappeared (for example, the previous marriage has been dissolved or the spouse has died) at the time of the application for annulment, the court generally does not support the application for annulment. But this is only a civil no longer annulment of post-marriage, does not mean that bigamists are not held criminally responsible。

7. the difference between bigamy and "cohabitation of a spouse with others"

The legal consequences of bigamy and those of “a person with a spouse cohabiting with another person” are significantly different. According to the Judicial Interpretation of the Marriage and Family Chapter, “cohabitation with another person by a person who is married” refers to a married person living together continuously and stably with an unmarried member of the opposite sex, without assuming the status of husband and wife. There are two key distinctions between it and bigamy: whether or not marriage registration has been completed, and whether the parties live together in public as husband and wife. Bigamy either involves formal registration or the couple lives together under the appearance of marriage; in contrast, “cohabiting with another person” explicitly means not presenting oneself as a married couple—there is continuous and stable cohabitation, but the relationship is not publicly acknowledged as marital.

Consequences: Bigamy not only involves the invalidation of marriage, but also may constitute the crime of bigamy; while "cohabitation of a spouse with others" does not constitute a crime, but it belongs to the situation of divorce damage compensation stipulated in Article 1091 of the Civil Code, and the innocent party can also claim compensation. Whether bigamy or cohabitation with others, are the legal grounds for determining the breakdown of feelings and granting divorce, and are also important considerations for "taking care of the rights and interests of the innocent party" in the division of divorce property, and the wrong party with serious circumstances may be significantly less divided in the division of common property. Although the term “leaving with nothing” is not a legally recognized concept, when there are serious marital faults such as bigamy, the innocent party may indeed obtain a more favorable outcome in matters such as property division and compensation for damages.

8. Frequently Asked Questions

Question 1: If there is only an extramarital affair and no second marriage registration, does that constitute the crime of bigamy?Generally not. To constitute bigamy or the crime of bigamy, there must be either a second legal marriage registration, or cohabitation as husband and wife without registration (de facto marriage). Simple adultery or cohabitation without the appearance of marriage generally does not constitute the crime of bigamy.

Question 2: If I register my marriage with a married person without knowing their marital status, will I also be guilty of bigamy?If one genuinely does not know that the other party is already married, and therefore lacks the requisite “knowledge,” it generally does not constitute the crime of bigamy; in such cases, only the party who is already married will be held accountable. At the same time, your marriage is void due to bigamy, and as the injured party, you may claim corresponding damages.

Question 3: How long is the heaviest sentence for the crime of bigamy? Article 258 of the Criminal Law stipulates that the crime of bigamy shall be sentenced to fixed-term imprisonment of not more than two years or criminal detention, and the sentencing range is limited, and probation may be applied to those who meet the conditions.

Question 4: In a bigamy case, is it necessary to file a police report? Can the court directly accept the case?In a case of bigamy, the public security organ may initiate an investigation, the procuratorate may bring a public prosecution, or the victim may file a private prosecution with the court. If the victim has evidence to support the claim, they may file a lawsuit directly with the court, which shall accept the case in accordance with the law.

Question 5: What evidence is required to file a lawsuit for bigamy? The core is to prove "the second registration" or "living together in the name of husband and wife", including marriage registration records, wedding or wedding photos and other external evidence in the name of husband and wife, public testimony, children's birth information, common property records, etc. Insufficient evidence is the primary reason why bigamy is difficult to establish.

Question 6: After bigamy is discovered, what will happen to the previous marriage?A prior lawful marriage is not automatically terminated by bigamy; it must still be dissolved through divorce in accordance with the law. Bigamy serves as a statutory ground for the faultless party to seek divorce, damages, and favorable treatment in the division of marital property; the subsequent marriage is deemed invalid on the basis of bigamy.

9. Lawyer's Practical Insights

The difficulty of bigamy case lies not in the law, but in the evidence. Because it not only affects the civil nullity of marriage, damages, but also may affect the criminal responsibility, so it should be prepared according to the idea of "both civil and criminal punishment" from the very beginning. Many people believe that as long as a second marriage certificate has not been obtained, it does not constitute bigamy; however, cohabiting as husband and wife without formal registration can also amount to bigamy. The key to judgment is not the depth of feelings or how long they live together, but whether there is any publicity of the identity of husband and wife: how to address them, whether they have held a banquet, whether they have signed a house purchase loan in the name of husband and wife, and whether the people around them generally think they are husband and wife. These are precisely the things that can be obtained and are most highly valued.

In terms of strategy, first secure the evidence at the “public disclosure” level, then decide which course of action to take. Collect as soon as possible documents such as proof of residence from the property management or community, jointly signed contracts, wedding banquet records or joint photographs, birth and medical registration records, and witness testimonies. For electronic evidence, be sure to preserve the original storage media. In civil proceedings, one may simultaneously claim damages in a divorce lawsuit and seek favorable treatment in the division of marital property; in criminal proceedings, one may file a report with the public security authorities and, if the conditions are met, also initiate a private prosecution in court. However, it should be clear that ordinary extramarital affairs and short-term cohabitation typically do not constitute bigamy. Elevating common transgressions to the level of bigamy mayOn the contrary undermine the credibility of such claims.

Evidence collection must adhere to legal boundaries; one must not rely on trespassing into private residences, illegally installing surveillance devices, or purchasing information to assemble a case file. Otherwise, the evidence will be excluded, and the party involved may even face legal repercussions. It is acceptable to use the criminal risk of bigamy as leverage during negotiations, but one must exercise restraint, aiming to reveal the facts and secure reasonable terms—rather than resorting to threats of reporting in order to extort excessive compensation. Doing so could easily shift the advantage into a liability. The overall strategy is to first firmly establish the “in the capacity of husband and wife” element, then pursue both civil and criminal avenues in parallel, engaging in negotiations while taking legal action, thereby leaving ample room for maneuver.

Back to the title:Bigamy is not merely a ground for “invalidating the marriage”; it may also constitute the crime of bigamy. It is a group of superposed responsibilities-in civil terms, bigamy is a legal cause of invalidity, the party without fault can claim compensation for divorce damages, and the disposal of invalid marital property caused by bigamy shall not infringe the rights and interests of legal spouses; in criminal terms, bigamy violates Article 258 of the Criminal Law and is liable to fixed-term imprisonment of not more than two years or criminal detention, and the third party who "knowingly marries others have a spouse" may also be prosecuted.

For the parties involved, here are a few pieces of advice worth remembering. First, determine the nature of the situation before taking action: clarify whether it constitutes an extramarital affair, cohabitation with another person, or bigamy, and decide whether to pursue civil or criminal proceedings. Second, we should attach importance to evidence and keep the bottom line. Evidence collection must be legal to avoid "being held accountable instead of safeguarding rights". Third, prioritize pursuing civil remedies to stabilize the situation: promptly challenge the validity of gifts to prevent asset outflow and seek the recovery of jointly owned property; if divorce is imminent, simultaneously assert a claim for damages in the divorce proceedings. Fourth, when criminal responsibility needs to be investigated, we should grasp the two paths of private prosecution and reporting, and apply to the court for investigation and collection of evidence when necessary.

Marriage is a legally protected relational status, and bigamy directly undermines the principle of monogamy. Understanding the rules is not meant to encourage confrontation, but rather to know how to protect oneself in a lawful and rational manner when one’s rights are violated.