International Law When people are planning to marry and live in different jurisdictions, or they have assets in different jurisdictions, they should consider entering into a prenuptial agreement. Their advisers or attorneys should consider the law of all jurisdictions, in order to make the best agreement for them.
However, this task is very difficult because the laws of each country are different. We call "conflict of laws" when the law of one country is opposite or different from the law of another country. Studying the laws of each country and following the intentions of the future spouses is capital.
There is only one International Treaty about prenuptial agreements. It's called "The Hague Convention on the Law Applicable to Matrimonial Property Regimes", which specifically authorizes prenuptial agreements. But only a few countries have ratified that treaty. Thailand have not.