A prenuptial agreement is a written agreement entered into by a prospective husband and wife before or during their marriage. The agreement typically regulates property, rights, obligations, or other agreed-upon matters, as long as they do not conflict with law, morality, or public order. This can be seen in Article 29 of Law No. 1 of 1974 concerning Marriage, which states:

1). At or before the marriage, both parties, with mutual consent, may enter into a written agreement that is approved by a marriage registrar. After that, the contents also apply to third parties, as long as they are involved.

(2) The agreement cannot be validated if it violates legal, religious, or moral boundaries.

(3) The agreement takes effect from the date of the marriage.

(4) During the marriage, the agreement cannot be amended unless both parties agree to the amendment and the amendment does not harm the third party. This is to protect assets, avoid future disputes, and provide legal certainty.