Polygamy is having more than one spouse at the same time. Bigamy is a form of polygamy and it involves one person getting legally married to multiple partners. Although polygamy is not illegal everywhere, many jurisdictions prohibit polygamy and bigamy and others ban only bigamy. Penalties for these offenses include fines and/or prison time. The severity of punishment depends on the jurisdiction.
Frequently, when polygamy occurs, it is a man that has multiple wives, i.e., polygyny. In some instances, a woman may have multiple husbands; this is called polyandry. Usually everyone involved in a polygamous relationship lives in the same household. Hence, the spouses are all aware that they are in a polygamous relationship.
Bigamy, however, is slightly different. A bigamist is a person who gets legally married to multiple partners without their knowledge. In others words, the persons married to a bigamist are unaware that their spouse has multiple marriages. A bigamist often maintains a home for each spouse in a different city to keep the marriages secret.
In the U.S., for example, the severity of punishment for polygamy and/or bigamy varies dramatically. Some jurisdictions classify these offenses as misdemeanors while others classify them as felonies. Fines range typically from $500 U.S. Dollars (USD) to $10,000 USD. Prison time in general may range from six months to nine years. Each jurisdiction may establish whatever penalties it deems appropriate, however.
In some jurisdictions, a good faith belief that a person obtained a legal divorce or an annulment is a valid defense against a charge of bigamy or polygamy. An annulment means that a court declared a marriage as invalid from its onset. A person’s ignorance of the law or a misunderstanding of the law is not a defense. U.S. courts also reject, as a defense, a religious belief that a particular faith approves of multiple spouses. In other words, freedom of religion cannot protect a polygamist from criminal prosecution.
Some jurisdictions that criminalize polygamy do not enforce the law or make minimal efforts at enforcement. For instance, in the U.S., Utah often failed to enforce its polygamy laws. Critics claimed it was due to the state’s large Mormon population that once believed that God approved of polygamy or plural marriages. Eventually, the Mormon Church renounced the practice. Nevertheless, some Mormons in the western U.S. still engage in polygamous relationships.
Polygamists in the U.S. complain that the government is violating their religious freedom and their right to privacy under the U.S. Constitution. They point out that the government does not prosecute a person for having multiple sex partners, having children with multiple partners, or living in the same place with multiple partners. Yet the government may prosecute a person for claiming the benefit of marriage to multiple partners. Polygamists believe this is unfair.