Section 4 — Offences within the Kingdom
English translation
Whoever commits an offence within the Kingdom shall be punished according to law.
An offence committed on a Thai vessel or Thai aircraft, wherever it may be, shall be deemed to have been committed within the Kingdom.
This English translation is provided for reference only and has not yet been firm-verified — always rely on the Thai original.
Firm annotation
Section 4 anchors the territoriality principle that opens the Code's rules on scope of application. Paragraph one establishes that Thai criminal law applies to offences committed within the Kingdom, regardless of the offender's nationality. Paragraph two adds the flag principle, extending the territorial reach to Thai-registered vessels and aircraft wherever they are. It works together with Section 5, which deems an offence committed within the Kingdom when even part of the act, or its intended or foreseeable result, occurs in the Kingdom, and with Sections 6 to 11, which govern participants abroad and true extraterritorial jurisdiction. Conduct that falls entirely outside these provisions is not punishable in Thailand unless a specific law extends liability.
Why this matters in practice
For most cases the key question is simply whether the offence happened in Thailand; if so, Thai law applies to Thais and foreigners alike. The practical friction arises with cross-border conduct: online fraud, cross-border scams, and transnational schemes often involve acts partly abroad. In those situations Section 4 must be read with Section 5, and if the conduct is genuinely wholly outside the Kingdom, prosecution in Thailand depends on whether an extraterritorial provision or a special statute applies. Foreigners should not assume that acting from abroad puts them beyond Thai jurisdiction where any part of the offence, or its result, touches Thailand.
Supreme Court decisions interpreting this section
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Supreme Court Judgment No. 1172/2566 (2023)
Section 4 punishes offences committed within the Kingdom; conduct occurring outside the Kingdom is not punishable in Thailand unless a law expressly provides for extraterritorial liability.
Citing Section 4 paragraph one and Section 5, the Supreme Court addressed whether public-fraud borrowing and unlicensed finance-business conduct occurring outside the Kingdom could be punished, holding that without a provision extending extraterritorial liability the court could not convict on those charges.
Curated decisions with case numbers verified against the Supreme Court database. English renderings are the firm's editorial translation for study.
Frequently asked questions
Does Thai criminal law apply to foreigners?
Yes. Under Section 4, anyone who commits an offence within the Kingdom is punishable under Thai law, regardless of nationality.
What about an offence committed on a Thai aircraft flying abroad?
Section 4 paragraph two deems an offence committed on a Thai vessel or Thai aircraft, wherever it is located, to have been committed within the Kingdom.
If part of an offence happens abroad, can Thailand still prosecute?
Often yes. Section 4 must be read with Section 5, which deems an offence committed within the Kingdom when even part of the act or its intended result occurs there.