The misunderstanding comes that you rely upon an English text instead of the actual Thai written law. I rely upon the actual Thai language written law.
1656 precedes 1657, 1658,... but doesn't "govern" or define 1657, ...
There are 5 different types of will
Section 1656 describes the first type of will, commonly known as พินัยกรรมแบบธรรมดา Here the testator can sign or even thumb print a printed will, with 2 witnesses.
Then section 1657 describes the second type of will, commonly known as พินัยกรรมแบบเขียนเองทั้งฉบับ --> this is the handwritten will we're talking about, thimbprint is not allowed. (Wouldn't make sense since this has to be completely handwritten by the testator)
These first 2 wills don't need registering. And the handwritten type (2nd type) doesn't need witnesses either.
Then there are 3 more types :
3.พินัยกรรมทำเป็นเอกสารฝ่ายเมือง --> 1658
4.พินัยกรรมทำเป็นเอกสารลับ --> 1660
5.พินัยกรรมทำด้วยวาจา --> 1663
You can't rely on English versions of the law you find on the internet. The English version is just a "more or less" translation with mistakes.
Aha, I see where the misunderstanding comes from :
You used section 1656, which is for the first type of will, which needs 2 witnesses. This is for a printed will. And furthermore you used an incorrect English text, not original Thai.
Handwritten will is section 1657, which doesn't need witnesses.
I base my comments on the original Thai text regarding the different types of wills described in Thai civil law. The difference between the 5 types are described in sections (มาตรา) 1656 to 1663 as part of the whole set of laws regarding Thai will.
This must be a misunderstanding, there is nothing in the specification of handwritten testament which limits the beneficiaries to legal partner.
There are 5 different types of testament specified in Thai law.
The handwritten type is the second one --> พินัยกรรมแบบเขียนเองทั้งฉบับ and described in ป.พ.พ. มาตรา 1657 : has to be entirely handwritten and properly signed (no thumbprint as signing) by the person and needs a date (day month year).
To read the law Article 1657 go to the source at
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%20law/pang01.htm
Then use the find function of your browser to look for 1657 and it will bring you to the specific Article for handwritten testament.