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    The content on this page is for general educational purposes and does not constitute legal advice. Every legal situation is unique. For matters involving investigation, arrest, litigation, or formal proceedings, consult a qualified legal professional.

    construction
    moderate offence

    Operating as Unlicensed Contractor in Thailand

    Performing controlled construction work without proper professional licensing

    Last updated: February 2026
    Legal Sections

    Professional Engineering Act B.E. 2505 (1962) §45, Architect Act B.E. 2543 (2000) §49

    Maximum Penalty

    Fine up to THB 50,000 and/or imprisonment up to 3 years

    Severity Level

    moderate

    Definition

    Performing controlled construction work without proper professional licensing Under Thai law, this offence is classified as a moderate offence within the category of construction.

    Elements of the Offence

    For a conviction, the prosecution must prove all of the following elements beyond reasonable doubt:

    1

    Performing engineering work without license

    2

    Designing buildings without architect license

    3

    Using unlicensed professionals for controlled work

    Penalties

    Maximum Penalty

    Fine up to THB 50,000 and/or imprisonment up to 3 years

    Actual sentences depend on factors including the severity of the conduct, harm caused, prior convictions, and mitigating circumstances. Courts have discretion to impose lesser sentences within the statutory range.

    Possible Defences

    The following defences may be available depending on the circumstances:

    Work below controlled threshold

    Supervision by licensed professional

    Note: The availability of defences depends on specific facts. Professional legal advice is essential.

    For Foreigners

    Special Considerations for Foreign Nationals

    Foreign engineers/architects must obtain Thai professional licenses to practice.

    When Legal Representation Matters

    If you are accused of operating as unlicensed contractor or facing investigation, immediate legal representation is essential to protect your rights and build an effective defence.

    Anglo Siam Legal provides experienced legal services across Thailand for both Thai nationals and foreigners.

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