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 secret will (พินัยกรรมแบบเอกสารลับ, phinaikam baep ekkasan lap, sometimes called a sealed will or secret document will) is a will whose contents stay private: the testator signs it, seals it, signs across the seal, and hands it to a district officer in front of at least two witnesses, declaring that it is their will (Section 1660 of the Civil and Commercial Code). The officer records the declaration on the cover and everyone signs. It is the least used of the forms Thai law recognises, but it suits a testator who wants an official record that a will exists without an official reading of what it says.
Table of Contents
What Section 1660 requires
The steps must be followed exactly. The testator signs the document itself, whether handwritten, typed or drafted by someone else. The document is closed, usually in an envelope, and the testator signs across the closure so that it cannot be opened without breaking the signature. The sealed document is then produced to the district officer (the amphur or khet officer) before at least two witnesses, and the testator declares that it is their will. If the testator did not write the text personally, they must also state the name and address of the person who did.
The officer writes the declaration and the date on the cover, applies the official seal, and the officer, the testator and the witnesses all sign the cover. The Code also allows a person who is deaf or cannot speak to make a secret will by writing on the cover, in the officer’s presence, that the document is their will. The general rules on witnesses and beneficiaries apply: the writer of the will, each witness and their spouses cannot take anything under it (Section 1653), and a witness must be an adult of sound mind who is not deaf, mute or blind.
When a foreigner might use one
The secret will answers a specific worry: the testator wants the district office to certify that a will exists and was made on a given date, but does not want the officer, the witnesses or the family to read it. A foreigner leaving assets unequally among Thai relatives, or naming a beneficiary the family would object to, may prefer it to a public will, which the officer writes out and reads aloud. Because the text is prepared beforehand, it can be bilingual and as detailed as the testator wishes.
The practical points are the same as for any district office attendance: passport or official identification, two adult witnesses who are not beneficiaries, and an interpreter if the testator does not speak Thai, since the declaration is made to the officer in Thai. The office charges a fee for the certification. The testator keeps the sealed document, so the same storage problem arises as with a private will; it must be somewhere the estate administrator can find it, and it is opened only at probate.
Where secret wills go wrong
The form has more formalities than any other and each is a point of failure. A signature missing from the document inside, a seal signed by the officer but not the testator, a declaration made to a clerk rather than the officer, or witnesses who were not both present, can all leave the court with a sealed envelope and no valid will. Because nobody reads the contents at the time, mistakes in the text itself, such as a gift to one of the witnesses, are found only after death, when nothing can be corrected.
For most foreigners a bilingual ordinary witnessed will under Section 1656, kept with a firm or a trusted person, gives the same privacy with fewer steps, and a public will gives a better official record. The secret will fills the narrow gap between them: privacy plus a certified date. The guide on making a last will in Thailand sets out all the forms side by side.
Frequently asked questions
What is a secret will under Thai law?
A will the testator signs, seals and signs across the seal, then presents to a district officer before at least two witnesses while declaring it to be their will, under Section 1660. The officer notes the declaration and date on the cover and seals it, and the officer, testator and witnesses sign the cover. The contents are not read.
Can a foreigner make a secret will in Thailand?
Yes. Any adult with capacity can, and the sealed document can be in English or bilingual. The declaration to the district officer is made in Thai, so a testator who does not speak Thai brings an interpreter, and the two witnesses must be adults who take nothing under the will.
What is the difference between a secret will and a public will?
Both are made at a district office before two witnesses. In a public will the officer writes down the testator’s wishes, reads them back and keeps a certified duplicate, so the contents are known. In a secret will the officer only certifies the sealed envelope and the declaration, so the contents stay private until the will is opened after death.
See also: public will, holographic will, will, testator, and the guide on making a last will in Thailand.
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