Article 27: Failure to pay taxes within the prescribed time shall result in a 1.5% monthly surcharge on the unpaid tax amount. Any fraction of a month shall be counted as a full month, calculated from the date the filing deadline passes until the date the tax is paid.

Article 22: If there is reason to suspect that a tax return has been filed incorrectly, the tax officer has the authority to issue a summons requiring the taxpayer to submit books, documents, and reliable evidence for clarification. If it is found that the return is incorrect or if the taxpayer refuses to comply with the order, they shall be liable for an additional penalty equal to the amount of tax due.

Article 26: If a tax return is not filed, the tax officer may issue a summons requiring the taxpayer to provide an explanation and assess the tax due. If the taxpayer refuses to pay or comply with the order, they shall be liable for an additional penalty equal to twice the amount of tax due.

Article 35: Failure to file tax returns (Form PND.90, 91, or 94) within the prescribed time shall be punishable by a fine not exceeding 2,000 Baht.

Article 37: In the case of intentional misrepresentation, submission of false evidence, or fraud to evade or attempt to evade taxes, the offender shall be imprisoned for a term of three months to seven years and fined not less than 2,000 Baht and not more than 200,000 Baht.

Article 37 bis: In the case of intentional neglect to file a tax return in order to evade taxes, the offender shall be imprisoned for a term not exceeding one year, or fined not more than 200,000 Baht, or both.