A prenuptial agreement can be one of the most important documents a couple signs before marriage. It can also be worthless if it is prepared or registered incorrectly. Under Thai law, a prenuptial agreement is primarily concerned with the property relationship between future spouses. It can help clarify property owned before marriage, management of property during marriage, businesses, investments, debts, financial contributions, treatment of specified assets, international property and what happens to property if the marriage ends.
But a Thai prenuptial agreement is not simply a private document that can be signed whenever the couple chooses. The formalities surrounding the marriage registration are critical. A badly timed or improperly registered document may fail to operate as a valid Thai statutory prenuptial agreement.
What Is a Thai Prenuptial Agreement?
A prenuptial agreement — commonly called a prenup — is an agreement made between two people before they marry concerning their property relationship. In Thailand it is commonly referred to as สัญญาก่อนสมรส. The relevant legal framework is found principally within the property provisions of Thailand's Civil and Commercial Code. If spouses do not make a valid special agreement concerning their property before marriage, their property relationship is governed by the default statutory matrimonial-property regime.
Timing and Registration — The Critical Rules
A Thai Prenup Must Be Done Before Marriage
This is the single most important practical point: a Thai statutory prenuptial agreement must be prepared before marriage and must satisfy the statutory formalities connected with the marriage registration.
A couple should not wait until after the marriage ceremony or registration and then attempt to create a Thai prenuptial agreement retrospectively. Once the marriage has already been legally registered, it may be too late to create the same type of statutory prenuptial agreement.
Do not rely upon: "We can sort the paperwork out next week."
Registration at the Time of Marriage
Thai law — principally Section 1466 of the Civil and Commercial Code — imposes specific formal requirements. A prenuptial agreement must be properly connected with the marriage registration. The statutory requirements include that it be made in writing, signed as required and entered into the marriage-registration process in accordance with Thai law.
If the necessary formalities are not satisfied, the agreement can be void as a prenuptial agreement.
Do not treat registration of the marriage and preparation of the prenup as two unrelated events. They need to be coordinated in advance.
Witnesses
Thai law also contains witness requirements for the prenuptial agreement under Section 1466. The agreement should therefore be prepared with the registration formalities already understood. Do not arrive at an Amphur or Khet with a document downloaded from the internet and assume the registrar must accept it. Confirm the practical requirements before the marriage-registration date.
Wedding Ceremony vs Legal Marriage Registration
A traditional, Buddhist, religious or family ceremony is not necessarily the legal registration of marriage. If the couple has held a ceremony but has not yet legally registered the marriage, there may still be time to prepare the agreement before civil registration.
But if the marriage has already been legally registered, the position is fundamentally different. The relevant date is the legal marriage-registration date, not necessarily the date of the celebration.
Can We Sign the Prenup After the Wedding?
If the marriage has not yet been legally registered, there may still be an opportunity. If the marriage has already been legally registered, the couple should not assume they can simply create the same Thai statutory prenup at a later stage.
Postnuptial Agreements
Couples should not assume a document signed after marriage automatically has the same legal status as a properly registered Thai prenuptial agreement. Thai law regulates agreements between spouses concerning property, and post-marriage agreements can raise different legal issues. Where a marriage is already registered, obtain advice on what lawful arrangements remain possible. Do not simply rename a late prenup a "postnup" and assume the problem has been solved.
Altering a Prenup After Marriage — Section 1467
Section 1467 of the Civil and Commercial Code restricts alteration of a prenuptial agreement after marriage. Any change generally requires authorisation from the court.
Do not sign a rushed document on the assumption that "We can easily fix it later." The ability to alter it is restricted. This is another reason to prepare the agreement carefully and correctly before the marriage-registration date.
The Default Statutory Regime
What Happens Without a Prenup?
If there is no valid prenuptial agreement, the spouses' property relationship is governed by the default provisions of Thai matrimonial-property law under Section 1465 and subsequent provisions of the Civil and Commercial Code. Two important concepts are relevant.
Separate Property
Sin Suan Tua
Broadly covers categories of separate property recognised by Thai law — including property owned before marriage, property used personally, property used for a profession, property received by inheritance and property received through certain gifts. Classification depends upon the law and the actual facts.
Marital Property
Sin Somros
Concerns marital property under the statutory regime. Certain property acquired during marriage may fall within Sin Somros, together with other categories identified by law. Do not reduce the Thai system to: "Anything after the wedding is automatically half each." That can be inaccurate.
Why Have a Prenup If Thai Law Already Protects Separate Property?
A prenup can still be valuable because it may provide useful clarity about pre-marriage assets, particular businesses, investment portfolios, family assets, financial management, treatment of specified property and international assets. A well-prepared agreement can reduce uncertainty and later disputes about what the parties intended. But it should not be oversold — for many straightforward marriages, the statutory regime already provides a reasonable framework.
Assets, Debts and Businesses
Record Your Existing Assets
Before signing the agreement, identify major assets belonging to each person. These may include:
- land;
- condominiums;
- houses;
- businesses;
- shares;
- bank accounts;
- investments;
- pensions;
- vehicles;
- intellectual property;
- valuable personal items;
- cryptocurrency;
- overseas property; and
- loans owed to either party.
Where appropriate, schedules of assets can help create a clearer record of the financial position before marriage.
Record Existing Debts
Assets are only half of the picture. Each person should also identify substantial liabilities such as:
- mortgages;
- personal loans;
- business borrowing;
- guarantees;
- tax liabilities;
- credit agreements; and
- other significant debts.
A prenup should not be prepared on the false assumption that one party has no liabilities when substantial debts actually exist.
Full Financial Disclosure
A sensible prenuptial process should involve meaningful disclosure. If one party hides significant property, debts or business interests, that can create future disputes. Both parties should understand the financial circumstances they are entering. A prenup should not be used as a mechanism for deception.
Businesses
Business owners often have strong reasons to consider a prenup. Questions may include:
- who owned the company before marriage;
- whether shares are separate property;
- how business income will be treated;
- whether additional shares may be acquired;
- what happens to retained profits;
- what happens if marital money is invested into the company;
- who controls the business; and
- how the business will be valued if a dispute arises.
The company may also have separate shareholder agreements or constitutional documents. A prenup should not be drafted without understanding those arrangements.
Family Businesses
Where a family business is involved, the concern may extend beyond the future spouses. Parents, siblings or other shareholders may be worried that a divorce could affect ownership or control. A prenup can form part of broader succession and business planning — but it must not attempt to rewrite company ownership that belongs to other people.
International Couples and Foreign Law
Foreign Law Clauses
International couples often ask whether they can simply state "English law will govern everything" or "Australian law will apply to our property." Thai law places restrictions on what can be stated in a Thai prenuptial agreement concerning the governing law of the spouses' property relationship.
Do not insert foreign-law clauses casually. An international couple may need separate advice in each relevant jurisdiction rather than assuming one clause in a Thai document controls everything everywhere.
International Couples
Prenups become more complicated where either spouse has connections with another country. Examples include:
- foreign nationality;
- overseas property;
- foreign companies;
- foreign pensions;
- investments abroad;
- children or family in another jurisdiction;
- plans to relocate overseas; or
- the possibility of divorce outside Thailand.
A prenup valid in Thailand is not automatically guaranteed to have identical effect in another country. Likewise, a foreign prenup is not automatically guaranteed to operate in Thailand exactly as it does in the country where it was created.
Will My Thai Prenup Be Enforced Overseas?
That depends upon the foreign jurisdiction. Another country's court may examine whether the agreement was valid where it was made, whether both parties obtained legal advice, disclosure, voluntariness, fairness, public policy, formal requirements and the foreign country's own family law. Couples with significant international assets should obtain advice in the jurisdictions where enforcement may eventually matter.
Will a Foreign Prenup Work in Thailand?
Do not assume that because an agreement is valid in another country it automatically satisfies Thai requirements. Where a couple intends to marry in Thailand and wants a Thai statutory prenup, Thai formalities need to be addressed. International planning should be coordinated before the wedding.
Thai-Foreign Marriages
Thai-foreign couples commonly consider prenups because their property arrangements can involve different legal systems. Potential issues include:
- Thai land;
- foreign property;
- condominiums;
- businesses;
- pensions;
- bank accounts;
- inherited assets;
- overseas investments; and
- children from earlier relationships.
The agreement should be tailored to the actual assets. A generic internet template is unlikely to address every international issue properly.
Same-Sex Couples
Thailand's marriage equality reforms took effect on 23 January 2025. Same-sex married couples are therefore part of Thailand's matrimonial-property framework. The same general Thai prenuptial rules apply. A same-sex couple considering marriage should address the prenup before registration just as any other couple would. Marriage equality did not create a separate type of LGBTQ+ prenup. For further detail on marriage equality in Thailand, see the Same-Sex Marriage & LGBTQ+ Rights guide.
Thai Land and Property
Foreigners and Thai Land — the Prenup Cannot Override the Law
A prenup does not override Thailand's restrictions on foreign ownership of land.
A clause saying "the foreign spouse owns half the Thai land" does not make prohibited land ownership lawful. The same applies to attempts to use a prenup to disguise a nominee arrangement. A private agreement cannot override mandatory Thai land law.
Land Purchased by the Thai Spouse
Where a Thai national married to a foreigner purchases land, Land Office requirements concerning the purchase funds and the Thai spouse's ownership can become relevant. A prenup should be drafted with awareness of these rules. Do not include language that directly contradicts declarations made to the Land Office. The documents surrounding the property transaction should tell a coherent legal story.
For a full explanation of the rules governing foreign nationals and Thai land, see the Foreign Land Ownership guide.
Houses and Buildings
Land and buildings can sometimes involve different legal rights. Where a foreign partner expects to finance construction on Thai land, the prenup should not be the only document considered. Separate property structures may need examination, including where appropriate:
- superficies;
- lease;
- usufruct;
- loan arrangements;
- ownership of the building; and
- contractual rights.
A prenup does not replace proper land and property planning. See also the Leasehold guide, Usufruct guide and Superficies guide.
Condominiums
Foreign nationals may be able to own qualifying condominium units subject to Thai condominium law. Where one or both future spouses own condominiums, identify clearly:
- current ownership;
- purchase date and funding;
- foreign quota considerations;
- mortgages; and
- intended treatment of the property.
Do not assume the prenup can override requirements under the Condominium Act. For detailed guidance, see the Condominium Act guide.
Inheritance, Children and What a Prenup Cannot Do
Prenuptial Agreements and Wills — Not the Same Thing
Prenup ≠ Will
A prenuptial agreement deals with the spouses' property relationship during marriage and on divorce. It is not a substitute for estate planning. Marriage itself affects inheritance rights.
A couple may also need to consider Thai wills, overseas wills, beneficiary nominations, life insurance, business succession, children from previous relationships and inheritance rules in other countries. These documents should be coordinated.
For detailed guidance on estate planning in Thailand, see the Wills and Estate Planning guide.
Children From Previous Relationships
A future spouse may want to preserve certain assets for children from an earlier relationship. A prenup can form part of that planning, but inheritance should also be addressed through proper estate planning. Do not rely entirely upon the prenup to determine what happens on death.
Child Custody — A Prenup Cannot Simply Predetermine It
A prenup should not be treated as a guaranteed mechanism for deciding future child custody. Statements such as "the mother will automatically get custody" or "the father can never claim parental power" should not simply be assumed enforceable because they appear in a prenup. Questions concerning children are governed by family law and the child's welfare. Future circumstances matter.
For guidance on custody and parental power, see the Divorce & Child Custody guide.
Child Support Cannot Simply Be Waived in Advance
Do not assume a prenup can permanently remove or restrict a child's legal rights. Child maintenance concerns the child, not simply a financial bargain between the future spouses. A clause attempting to predetermine every future child-support issue may not operate as the parties expect.
A Prenup Does Not Prevent Divorce
A prenup is not a contract requiring two people to remain married forever. It can regulate lawful property arrangements. It does not remove statutory rights to seek divorce where Thai law permits it.
A Prenup Does Not Guarantee No Litigation
A clear agreement can reduce disputes, but it cannot guarantee litigation will never occur. Disputes may still arise about validity, interpretation, property classification, asset ownership, disclosure, compliance, international enforcement and issues outside the scope of the agreement. The goal is to reduce uncertainty, not promise that conflict is impossible.
Unfair, Extreme and Personal-Behaviour Clauses
Thai law restricts clauses contrary to public order or good morals under the Civil and Commercial Code. Extreme provisions can create validity and enforcement problems. The agreement should focus on lawful property arrangements rather than punishment or control.
Infidelity-penalty and personal-behaviour clauses — covering household chores, social activities, religion, appearance or lifestyle rules — require careful legal analysis. Do not assume that any clause written into a contract will automatically be enforceable. Keep the document focused on its legitimate property purpose.
Practical Guidance
Independent Legal Advice
Ideally, each future spouse should understand the document independently. This is particularly important where:
- one person is substantially wealthier;
- one party owns a business;
- there are international assets;
- the document is drafted by only one party's lawyer;
- one party does not read Thai;
- one party does not read English;
- there is family pressure; or
- the wedding date is close.
A person should not sign a major financial agreement simply because their partner says "My lawyer says it's fine."
Translation
If one party cannot read Thai, the agreement should be properly explained and, where appropriate, prepared bilingually or translated. Do not sign a legal agreement in a language you cannot understand and rely entirely upon the other person's verbal summary.
Avoid Last-Minute Prenups
Preparing the agreement the night before the wedding is poor practice. The couple should allow time to:
- identify assets;
- disclose finances;
- obtain legal advice;
- negotiate terms;
- translate documents;
- correct errors;
- confirm registration arrangements; and
- understand the final agreement.
A prenup should be planned, not rushed.
Coordinate With the Amphur or Khet
Outside Bangkok, marriage registration is completed at an Amphur/Amphoe (อำเภอ). In Bangkok, registration is handled through a Khet (เขต) district office. Where a prenup is involved, contact the intended office in advance. Administrative practice and document expectations should be confirmed before the wedding day. Do not simply arrive with the document and assume the registrar must accept it in any form.
Documents You May Need
The exact registration package depends upon the couple's circumstances. Documents may include:
- passports;
- Thai ID cards;
- house-registration documents;
- freedom-to-marry documentation for foreign nationals;
- translations and legalised documents;
- previous divorce or death certificates where applicable;
- the final prenuptial agreement; and
- required witnesses.
Confirm the current checklist with the actual registrar. Do not rely solely upon an old online checklist.
British Nationals
British nationals marrying in Thailand should separately follow the current British and Thai requirements for establishing freedom to marry. The prenup process does not replace those marriage-document requirements. The couple should coordinate foreign marriage documentation and translation/legalisation with preparation of the prenup and marriage registration — do not leave the prenup until the consular paperwork is finished if the marriage-registration date is approaching. Check the current requirements at GOV.UK — Marriage Abroad.
After Marriage Registration — Keep the Documents
After marriage registration, keep secure copies of:
- the prenuptial agreement;
- marriage-registration documents;
- asset schedules;
- financial disclosure;
- translations;
- legalisation documents;
- title documents; and
- relevant correspondence.
Do not assume the document will never be needed.
If You Are Already Married
If the marriage is already legally registered and no valid prenup was put in place, do not attempt to backdate a document.
Backdating creates serious legal and evidential problems. Instead, obtain advice on the property arrangements that remain legally available to married spouses. The answer may be different from what could have been done before marriage.
If You Are Already Cohabiting
Cohabitation itself does not prevent a future prenup. The critical question is whether the couple has already legally married. A couple can live together for years and still prepare an appropriate prenup before marriage registration — this can be particularly useful where the couple has already accumulated shared assets. For more on the legal position of unmarried couples, see the Cohabitation & Unmarried Partners guide.
Checklists
Practical Prenup Checklist
Start early — do not wait until the wedding day.
List major assets belonging to both parties.
List existing debts including personal and business liabilities.
Record shareholdings and business ownership.
Identify all relevant foreign property and jurisdictions.
Do not draft clauses that conflict with Thai foreign land-ownership restrictions.
Coordinate the prenup with wills and estate planning where children from earlier relationships are involved.
Obtain independent advice — particularly where wealth or bargaining power differs substantially.
Ensure both parties properly understand what they are signing.
Translate the agreement properly where necessary.
Confirm Amphur or Khet requirements before registration day.
Sign and register correctly — do not separate the prenup from the marriage-registration process.
Retain the agreement and all supporting documents securely.
Common Prenup Mistakes to Avoid
Preparing it after marriage registration.
Failing to comply with registration formalities.
Using an internet template without reviewing Thai law requirements.
Failing to identify major assets.
Hiding debts or business interests.
Ignoring foreign property or overseas assets.
Including clauses that unlawfully attempt to create foreign land ownership.
Assuming a foreign governing-law clause overrides Thai matrimonial-property rules.
Trying to permanently determine child custody in advance.
Attempting to waive future children's rights to maintenance.
Using punitive personal-behaviour clauses.
Failing to obtain translation.
Signing under pressure without independent advice.
Preparing it at the last minute without time for proper review.
Failing to coordinate with the Amphur or Khet.
Assuming it can easily be rewritten after marriage.
In Summary
Key Points to Remember
A Thai prenuptial agreement must be dealt with before and in connection with legal marriage registration.
Do not wait until after the marriage is registered — it may be too late to create the same statutory prenup.
The agreement must satisfy Thai statutory formalities, including written form, signatures, witnesses and connection to the marriage-registration process.
Alteration after marriage is restricted and generally requires court authorisation under Section 1467.
Without a valid prenup, Thailand's statutory matrimonial-property regime applies — Sin Suan Tua and Sin Somros are the relevant concepts.
A prenup can help clarify businesses, investments, property and international assets.
It cannot override Thailand's foreign land-ownership restrictions.
It should not be assumed to permanently determine child custody or eliminate children's maintenance rights.
A Thai prenup is not guaranteed to have identical effect in another country.
A foreign prenup should not automatically be assumed to satisfy Thai requirements.
Same-sex spouses are subject to the same general prenuptial framework following marriage equality.
Do not sign a document you cannot understand.
Do not backdate a prenup.
Plan the agreement well before the marriage-registration date.
Legal Basis and Authoritative Sources
This guidance has been prepared with reference to the following authoritative sources:
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