Commercial and Civil Code of Thailand:
Section 1465 Where the husband and wife have not, previous to their marriage, concluded a special agreement concerning their properties, the relations between them as regards to their properties shall be governed by the provisions of this chapter.
Section 1466 The prenuptial agreement is void if not entered with the Marriage Register at the time of marriage registration terms of the prenuptial; or if not made in writing and signed by both parties and by at least two witnesses and entered with the Marriage Register at the time of marriage registration stating that the prenuptial is there to annexed.
Section 1467 After marriage the prenuptial agreement cannot be altered except by authorization of the court. When there is final order of the court to effect the alteration of cancellation of the prenuptial agreement, the court shall notify the Marriage Registrar of the matter in order to have it entered with the Marriage Register.
Section 1468 Clauses in the prenuptial agreement shall have no effect as regards to the rights of third persons acting in good faith irrespective of whether they be altered or cancelled by the order of the Court.
A Conflict of Laws Act:
Section 22 As regards to the property of husband and wife, if there is no ante-nuptial agreement, the law of nationality shall govern. If the husband and the wife have different nationalities, the property of husband and wife shall be governed by the law of nationality of the husband. However, as regards immovable property, the law of the place where such property is situated shall govern.
Section 23 The effects of marriage as governed by the two foregoing sections shall not be affected if, after marriage, either or both spouses acquire a nationality different from the nationality possessed or acquired at the time of marriage.
Section 24 As regards the property of husband and wife, if an ante-nuptial agreement is made, the capacity for making such agreement shall be governed by the law of nationality of each party.
Section 25 If the parties have the same nationality, the essential elements and effects of an ante-nuptial agreement shall be governed by the law of common nationality of the parties. If they have different nationalities, such essential elements and effects shall be governed by the law under which the parties intended or may be presumed to have intended to submit themselves; in the absence of such intention, the law of the first matrimonial domicile shall govern. However, as regards immovable property, the law of the place where such property is situated shall govern.