Division of assets in a divorce under Thai divorce laws
In a mutual consent divorce it depends on what you can agree with your spouse, there is no judge or court involvement but you have to agree on certain subjects (read link to sections divorce laws in Thailand below) and register the divorce and terms with the local amphur (municipality). When it is a contested divorce, when you cannot agree with your spouse on the terms of divorce, it is decided for you by a judge in court based on the law and sometimes individual circumstances.
Section 1533 Upon divorce, the matrimonial property shall be divided equally between man and woman.
มาตรา 1533 เมื่อหย่ากันให้แบ่งสินสมรสให้ชายและหญิงได้ส่วนเท่ากัน
Section 1535 Upon termination of the marriage, the man and woman shall be liable for common debts equally.
มาตรา 1535 เมื่อการสมรสสิ้นสุดลง ให้แบ่งความรับผิดในหนี้ที่จะต้องรับผิด ด้วยกันตามส่วนเท่ากัน
To understand 'property of the marriage' or jointly owned property of husband and wife in Thailand I recommend reading the law sections governing Marriage and Property. To understand divorce law and division of assets, responsibilities, grounds for divorce and such I recommend reading Thailand Divorce laws.
When only marital property (and marital debts) is divided equally, and personal property not, it often comes down to what you can prove in court what your personal property is, because in case of doubt (section 1474 Thai Marriage Laws) as to whether a property is a matrimonial asset or not it shall be presumed to be jointly owned marital asset, (in Thai ถ้ากรณีเป็นที่สงสัยว่าทรัพย์สินอย่างหนึ่งเป็นสินสมรสหรือมิใช่ ให้สันนิษฐาน ไว้ก่อนว่าเป็นสินสมรส). Marital property is a matter of calculating from the date of marriage. A good way to prevent discussions over assets is to do a prenuptial agreement, list your personal assets at the time of mariage and keep a form of accounting of personal assets (with proof) and property of the marriage during the course of the marriage.
See also