Section 15: Punishment converted into a measure of safety
Statutory text (Thai original)
ถ้าตามบทบัญญัติของกฎหมายที่บัญญัติในภายหลัง โทษใดได้เปลี่ยนลักษณะมาเป็นวิธีการเพื่อความปลอดภัย และได้มีคำพิพากษาลงโทษนั้นแก่บุคคลใดไว้ ก็ให้ถือว่าโทษที่ลงนั้นเป็นวิธีการเพื่อความปลอดภัยด้วย ในกรณีดังกล่าวในวรรคแรก ถ้ายังไม่ได้ลงโทษผู้นั้น หรือผู้นั้นยังรับโทษอยู่ ก็ให้ใช้บังคับวิธีการเพื่อความปลอดภัยแก่ผู้นั้นต่อไป และถ้าหากว่าตามบทบัญญัติของกฎหมายที่บัญญัติในภายหลังมีเงื่อนไขที่จะสั่งให้มีการใช้บังคับวิธีการเพื่อความปลอดภัย อันไม่อาจนำมาใช้บังคับแก่กรณีของผู้นั้น หรือนำมาใช้บังคับได้ แต่การใช้บังคับวิธีการเพื่อความปลอดภัยตามบทบัญญัติของกฎหมายที่บัญญัติในภายหลังเป็นคุณแก่ผู้นั้นยิ่งกว่า เมื่อสำนวนความปรากฏแก่ศาล หรือเมื่อผู้นั้น ผู้แทนโดยชอบธรรมของผู้นั้น ผู้อนุบาลของผู้นั้นหรือพนักงานอัยการร้องขอต่อศาลให้ยกเลิกการใช้บังคับวิธีการเพื่อความปลอดภัย หรือร้องขอรับผลตามบทบัญญัติแห่งกฎหมายนั้น แล้วแต่กรณี ให้ศาลมีอำนาจสั่งตามที่เห็นสมควร
English translation
If, under the provisions of a law enacted afterwards, any punishment has been changed in character into a measure of safety, and judgment imposing that punishment has been given against any person, the punishment so imposed shall be deemed to be a measure of safety.
In the case mentioned in paragraph one, if that person has not yet undergone the punishment, or is still undergoing it, the measure of safety shall continue to be applied to that person. And if, under the provisions of the law enacted afterwards, there are conditions for ordering the application of a measure of safety which cannot be applied to the case of that person, or which can be applied but the application of the measure of safety under the law enacted afterwards is more favourable to that person, then, when it appears to the court from the record, or when that person, that person's legal representative, that person's curator, or the public prosecutor applies to the court for the application of the measure of safety to be cancelled, or applies to receive the benefit under the provisions of that law, as the case may be, the court has the power to make such order as it thinks fit.
ThaiLawOnline translation, written from the Thai original and verified
Firm annotation
Section 15 completes the transitional scheme for safety measures in Sections 12 to 14 by dealing with a legislative shift in character, where a later law recharacterizes a penalty as a safety measure. Three consequences follow: a penalty already imposed is deemed a safety measure; for a person not yet punished or still undergoing punishment, the court may substitute a safety measure for the penalty; and where changed conditions would justify revocation, the court may revoke. The provision reflects the forward-looking, protective purpose of safety measures and the favourable-law policy running through this part of the General Part. It should not be confused with identically numbered sections in special statutes, which are unrelated provisions.
Why this matters in practice
Section 15 becomes relevant only when a reform re-labels a penalty as a safety measure, which is uncommon but consequential. Where it applies, a person still serving or awaiting a penalty may seek an order substituting the safety measure, which typically carries different conditions and review mechanisms than imprisonment. Because a safety measure is preventive rather than punitive, the possibility of later revocation on changed conditions is built in. If a legislative change of this kind affects a current sentence, it is worth examining whether Section 15 permits substitution or revocation. Note carefully that many drug-case citations to a section 15 refer to the Narcotics law, not to this provision.
Cited in 33 Supreme Court decisions (1958 to 2020)
Selected citing decisions
- Decision 6931/2550 (2007)
- Decision 6744/2548 (2005)
- Decision 217/2547 (2004)
- Decision 5385/2544 (2001)
- Decision 1980/2542 (1999)
- Decision 2887/2540 (1997)
- Decision 69/2538 (1995)
- Decision 1054/2535 (1992)
This list is selected automatically, weighted towards judgments that turn on this section rather than ones that merely recite it when passing sentence. It has not yet been reviewed by the firm.
Most often cited alongside
- Section 78 21
- Section 91 17
- Section 83 13
- Section 90 9
- Section 29 8
- Section 30 8
Sections that appear in the same judgments as this one most often. The figure is the number of decisions.
Counted across the firm's corpus of 83,652 Supreme Court decisions, 1921 to 2026. The count is complete; the stated year range trims rare outliers so it describes where the citations actually sit. These figures are computed by us and are not official court statistics. How we count these, and what we measured
Frequently asked questions
What happens if a later law turns a penalty into a safety measure?
Under Section 15, a penalty already imposed is deemed a safety measure, and for a person still serving or awaiting punishment the court may order a safety measure in place of the penalty.
Can a converted safety measure later be revoked?
Yes. Section 15 provides that where a change of conditions would justify revocation of the safety measure, the court may order it revoked.
Related guides on ThaiLawOnline
Cite this section
-
Plain citation
Penal Code, s. 15 (Thailand) -
Academic citation
Penal Code (Thailand), s. 15. ThaiLawOnline, https://www.thailawonline.com/thai-penal-code/section-15/ (accessed 17 August 2026). -
Thai citation
ป.อ. มาตรา 15 -
Permalink
https://www.thailawonline.com/thai-penal-code/section-15/ -
Embed on your site
<blockquote cite="https://www.thailawonline.com/thai-penal-code/section-15/"><p>If, under the provisions of a law enacted afterwards, any punishment has been changed in character into a measure of safety, and judgment imposing that punishment has been given against any person, the punishment so imposed shall be deemed to be a measure of safety.…</p><footer>Penal Code, s. 15 (Thailand) — <a href="https://www.thailawonline.com/thai-penal-code/section-15/">ThaiLawOnline</a></footer></blockquote>
The Thai text is authoritative. The English is an unofficial translation by ThaiLawOnline, free to reuse with attribution.