Is bigamy grounds for annulment in the Philippines?

No. The grounds for annulment are those issues that happened before the marriage.

The grounds for annulment of marriage are:

1. Absence of Parental Consent. A marriage was solemnized and one or the other party was eighteen (18) years of age or over but below twenty-one (21) and consent was not given by the parents, guardian or person having substitute parental authority. The Petition of Annulment must be filed within five (5) years of having attained the age twenty-one. However, if the parties freely cohabited with the other as husband and wife after having reached the age of twenty-one (21) a Petition of Annulment can no longer be filed.

2. Mental Illness. One or the either party was of unsound mind at the moment of the marriage. But if the parties freely cohabited with each other after he or she came to reason the law prohibits the filing of a Petition.

3. Fraud. That the consent of either party was obtained by fraud, unless such party once having knowledge of the fraud freely cohabited with the other as husband and wife. The petition must be filed within five (5) of finding out the facts of the fraud.

4. That the consent of either party was obtained by force, intimidation or undue influence. Except when the same has ceased and the party filing the petition freely cohabited with the other as husband and wife. The injured party must file within five (5) years from the point in time the force, intimidation or undue influence disappeared or came to an end.

5. One or the other party was physically incapable of consummating the marriage, and such incapacity continues and appears to be incurable. The filing of the Petition of Annulment must be filed within five (5) years after the marriage.

6. Either party was at the time of marriage afflicted with a sexually-transmitted-disease (STD) found to be serious and seems to be incurable. This may also constitute fraud. The filing of the Petition of Annulment must be filed within five (5) years after the marriage.