Reviewed by ThaiLawOnline, a licensed Thai law firm practising in Thailand since 2006. Thai lawyer of record: Wichuda Atthamethakon, LL.M., Thai Bar Licence 3149/2556.
Last updated on September 5, 2026
A void juristic act (โมฆะ, mokha, sometimes moghah) is one the law treats as never having existed, while a voidable act (โมฆียะ, mokhiya) is valid until the protected party cancels it, and becomes fully valid if that party ratifies it. The distinction runs through Sections 150 to 181 of the Civil and Commercial Code and decides whether a contract or a land transaction can be rescued or is beyond saving. For foreigners it matters most in nominee structures, contracts signed under pressure and deals done without the right form.
Table of Contents
What makes an act void or voidable
Void. A juristic act is void when its object is prohibited by law, impossible, or contrary to public order or good morals (Section 150); when it lacks a form the law requires (Section 152), for example a sale of land not registered at the Land Office; or when it is a sham declaration made with the other party’s connivance (Section 155). A void act cannot be ratified (Section 172), anyone with an interest may rely on its nullity at any time, and money paid under it is recovered under the rules on undue enrichment.
Voidable. An act is voidable when consent was defective: a mistake as to the qualities of a person or thing (Section 157), fraud that induced the act (Section 159), or duress (Section 164). Acts by a minor without the guardian‘s consent (Section 21) are voidable too. Only the protected person, or their heirs or guardian, may avoid or ratify it (Sections 175 and 177). Avoidance is retroactive (Section 176). The right is lost one year after ratification became possible and in any case ten years after the act (Section 181).
Where a foreigner meets the distinction in practice
The clearest example is land. An arrangement in which a Thai national holds land as a nominee for a foreigner breaches the Land Code and is void under Section 150: the foreigner cannot enforce it, and the land can be ordered sold. A postnuptial agreement is the mirror image: valid, but voidable at the wish of either spouse under Section 1469, which is why it gives so little security.
Condominium buyers see Section 152: a promise to sell a unit is enforceable, but ownership passes only by registration. Anyone who signed under pressure, or on the strength of a false statement about title or foreign quota, has a voidable act and must act within the year: continuing to pay instalments or accepting benefits under the contract counts as ratification (Section 180).
Void, voidable and unenforceable compared
| Feature | Void (mokha) | Voidable (mokhiya) |
|---|---|---|
| Status | Never took effect | Valid until avoided |
| Who can raise it | Any interested person, and the court | The protected party only |
| Ratification | Impossible | Possible, expressly or by conduct |
| Time limit | None | 1 year from possible ratification, 10 years from the act |
| Typical case | Nominee land holding, unregistered land sale | Fraud, duress, mistake, minor’s contract |
A third category is confused with both. A loan over 2,000 baht without written evidence is neither void nor voidable: the loan exists, but the lender cannot sue on it (Section 653). And a partly void act survives if the parties would have entered into the valid part alone (Section 173), which is how a lease whose term exceeds 30 years is cut back rather than struck out.
Frequently asked questions
What is the difference between void and voidable in Thai law?
A void act (mokha) is treated as never having existed, cannot be ratified and can be challenged by anyone at any time. A voidable act (mokhiya) is valid until the protected party cancels it, can be ratified, and must be avoided within one year of ratification becoming possible and ten years of the act.
Is a nominee agreement for land void in Thailand?
Yes. An agreement under which a Thai holds land for a foreigner is contrary to the Land Code and void under Section 150 of the Civil and Commercial Code. The foreigner cannot enforce it, and the authorities can require the land to be sold.
How long do I have to cancel a contract signed under fraud or duress in Thailand?
One year from the moment the fraud or duress ended and ratification became possible, and never more than ten years from the act (Section 181). Continuing to perform the contract after learning the truth can amount to ratification, so the notice of avoidance should be sent promptly and in writing.
See also: Good morals, Nominee, Postnuptial agreement (Section 1469), Thai Civil and Commercial Code and Thai legal system explained.
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