Why a Marriage Contract Matters in Thailand
When getting married in Thailand, international couples have a powerful tool for financial planning: a Thai marriage contract. Known in Thai as Sanya Kon Somros (literally, “contract before marriage”), this legal document is what most foreigners refer to as a prenuptial agreement, or simply a “prenup”. It isn’t about planning for divorce — it’s about creating clarity and protection for both partners from the start.
Since the Marriage Equality Act came into effect on January 23, 2025, all couples—regardless of gender—now share the same marriage and property rights. Understanding how Thai law divides assets has never been more important.
The Basics: Separate vs. Marital Property
Under Thai law, assets fall into two legal categories that determine ownership and division upon divorce.
Sin Suan Tua (Separate Property)
This refers to property belonging exclusively to one spouse and not subject to division after divorce. It includes:
- Property owned before the marriage.
- Personal-use items, such as clothing, jewelry, or professional tools.
- Property acquired by inheritance or gift during the marriage (unless expressly declared joint property).
- The dowry (Sin Sod) paid to the bride’s family and engagement gifts (Khongman) given to the bride remain her separate property under Section 1471 of the Civil and Commercial Code.
- Any property acquired in exchange for or from the sale of existing Sin Suan Tua.
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Sin Somros (Marital Property)
This is jointly owned property, to be divided equally (50/50) if the marriage ends, as per Section 1533 of the CCC.4 It includes:
- Property acquired during the marriage.
- Inheritance or gifts declared in writing as joint property.
- Income generated from personal property (the “fruits” rule — see below).
- Property purchased with joint marital funds.
Legal presumption: If there is any doubt whether an asset is separate or marital, the law presumes it to be marital property under Section 1474 of the Civil and Commercial Code.
The #1 Mistake Foreigners Make: The “Fruits” Rule
Under Thai law (Section 1474(3) of the CCC), any income (“fruits”) generated from your separate property during the marriage becomes marital property by default.
Example:
- You own a condo before marriage — the condo remains separate.
- But rental income earned during the marriage is marital and split 50/50 in a divorce.
- The same applies to stock dividends or interest from pre-marriage accounts.
👉 The only way to keep these “fruits” separate is by stating it explicitly in your prenup.
Making Your Prenup Legally Binding: The Three Golden Rules
Thai law is strict — if you miss any step, the agreement is void under Section 1466 of the CCC.
- It must be in writing. Verbal agreements don’t count.
- It must be signed by both partners and two adult witnesses (aged 20 or older under Thai law).
- It must be registered at the Amphur (District Office) at the same time as the marriage. The prenup should be drafted and reviewed 6-8 weeks beforehand, but the formal registration must happen on the wedding day. You cannot register it before or after.
What a Thai Prenup Can and Cannot Do
✅ A Prenup Can:
- List your separate assets to avoid future disputes.
- Protect business interests and future inheritances.
- Keep “fruits” (rent, dividends, interest) of your separate property separate.
- Let one spouse manage specific marital assets without joint consent, as per Section 1476 of the CCC.
🚫 A Prenup Cannot:
- Decide child custody, child support, or waive future court-ordered spousal maintenance (alimony). Thai courts retain discretion on these matters under public policy and Section 1526 of the CCC.
- Be grossly unfair. For example, an agreement giving one spouse 100% of all marital assets would likely be voided by a court for violating Section 1465’s public order principle, as confirmed in Supreme Court Judgement no. 195/2564.
- Apply foreign law to assets in Thailand.
Key Tips for International Couples
1️⃣ Get Independent Lawyers
Each partner should have their own lawyer. While not a strict requirement for validity in Thailand, it is essential for preventing claims of pressure or misunderstanding and is critical for recognition abroad (e.g., US, UK, Australia).
2️⃣ Use a “Dual-Prenup” Strategy
If you have assets both in Thailand and abroad, this is the most sophisticated approach:
- Create a Thai prenup for Thai-based assets.
- Create a foreign prenup (under your home country’s law) for assets outside Thailand. Both documents should complement, not contradict, each other.
Why Postnuptial Agreements Don’t Work
In Thailand, post-marriage property agreements can be revoked unilaterally by either spouse under Section 1469 of the Civil and Commercial Code — even during marriage. This makes them unreliable for long-term protection. Thai courts consistently uphold this principle, emphasizing that agreements made during marriage cannot override the Civil Code’s matrimonial property framework.
The Marriage Equality Act: Prenups for All Couples
The Marriage Equality Act, which took effect on January 23, 2025, replaces gendered terms like husband and wife with spouses. Same-sex couples now have equal rights to marry, adopt, inherit, and sign prenuptial agreements under the same rules as opposite-sex couples. That means the same financial protections — and risks — apply to everyone.
Final Checklist ✅
DO:
- Start 6–8 weeks before the wedding.
- Hire separate, independent lawyers.
- Make the agreement bilingual (Thai + your native language).
- Register the prenup together with the marriage at the Amphur.
DON’T:
- Rely on a verbal or unregistered agreement.
- Include clauses about child custody or alimony.
- Wait until after the wedding — it will be void.
Required Documents for Marriage & Prenup Registration
| Document | Foreign Partner | Thai Partner |
| Passport (original + copy) | ✅ | N/A |
| Thai National ID card | N/A | ✅ |
| House Registration (Tabien Baan) | N/A | ✅ |
| Affirmation of Freedom to Marry (from embassy) | ✅ | N/A |
| Thai translation of Affirmation, legalized by MFA | ✅ | N/A |
| Divorce or Death Certificate (if applicable) | ✅ | ✅ |
| Name Change Certificate (if applicable) | ✅ | ✅ |
| Signed bilingual prenuptial agreement (2 originals) | ✅ | ✅ |
| Two adult witnesses for marriage and prenup | ✅ | ✅ |
Note on Registration: The process at the Amphur usually takes 20-30 minutes if all documents are in order. Procedures can vary slightly by district, so it’s wise to call ahead. The registration fee is nominal or free.
Frequently Asked Questions (FAQ)
Q1: Can we change the “fruits rule” in a Thai prenup?
Yes — this is one of the main reasons to have one. By default, Section 1474(3) of the CCC treats the “fruits” of your separate property (rent, dividends, interest) as marital property during the marriage. But that default only applies if you haven’t agreed otherwise. Section 1465 expressly lets couples set their own property terms before marriage, so you can keep these fruits as separate property (Sin Suan Tua) — provided you do two things:
- Say it explicitly and register it. The prenup must spell out that the fruits of each spouse’s separate property remain separate, and it must be signed and registered together with the marriage under Section 1466. A vague or unregistered clause won’t achieve it.
- Keep the overall deal fair. A court can still set a clause aside if the agreement as a whole is grossly one-sided, under Section 1465’s public-order rule. Keeping the income from your own property is standard; stripping the other spouse of everything is not.
So the fruits rule is a default you can opt out of with the right clause — not a fixed definition you’re stuck with.
Q2: What happens if we don’t register the prenup on the wedding day?
It is legally void. Section 1466 of the CCC is absolute on this point. The agreement has no legal effect if it is not registered at the exact same time as the marriage.
Q3: Is a Thai prenup enforceable in my home country?
It depends. Countries like the US, UK, and Australia will scrutinize the agreement for fairness, full financial disclosure, and whether both parties had independent legal advice. This is why the “Dual-Prenup” strategy is highly recommended for international couples.
Need Expert Help?
At AIM Bangkok Business & Legal Solutions, we assist both foreign and Thai partners with:
- Drafting Thai–English prenuptial agreements
- Coordinating with foreign lawyers for dual-prenup strategies
- Preparing document checklists for Amphur registration
- Advising on property and inheritance planning
📍 Based in Bangkok — working with clients across Thailand and internationally.
Disclaimer: This article provides general information and does not constitute legal advice. Please obtain professional advice tailored to your situation.
