What is bigamy?

Article 349 of the Revised Penal Code prohibits a second or subsequent marriage before the legal dissolution of a first marriage:
Art. 349. Bigamy. - The penalty of prision mayor shall be imposed upon any person who shall contract a second or subsequent marriage before the former marriage has been legally dissolved, or before the absent spouse has been declared presumptively dead by means of a judgment rendered in the proper proceedings.
The second or subsequent marriage contemplated under this provision is the marriage entered into under the law. Article 1 of the Family Code defines marriage as "a special contract of permanent union between a man and a woman entered into in accordance with law for the establishment of conjugal and family life[.]"

Thus, the validity of the second marriage, if not for the subsistence of the first marriage, is considered one of the elements of the crime of bigamy. The elements of bigamy are:
(a) the offender has been legally married; (b) the marriage has not been legally dissolved or, in case his or her spouse is absent, the absent spouse could not yet be presumed dead according to the Civil Code; (c) that he contracts a second or subsequent marriage; and (d) the second or subsequent marriage has all the essential requisites for validity. The felony is consummated on the celebration of the second marriage or subsequent marriage. It is essential in the prosecution for bigamy that the alleged second marriage, having all the essential requirements, would be valid were it not for the subsistence of the first marriage.[44] (Emphasis supplied, citations omitted)