Missing a tax filing deadline or submitting an incorrect return in Thailand can quickly become expensive for a company. Depending on the violation, companies may face monthly surcharges, additional tax assessments and, in certain cases, personal liability for their directors. Here are some of the most common compliance issues faced by businesses in Thailand, along with the penalties and additional costs they can generate.
What happens when taxes are paid late?
Thai companies file several tax returns every month: withholding tax, payroll tax and, for VAT-registered businesses, VAT. Deadlines vary depending on the type of tax. Late tax payments are subject to a monthly surcharge of 1.5%, to be paid to the Revenue Department. This starts the day after the deadline, and even part of a month counts as a full month. At 1.5% per month, the surcharge reaches 18% after 12 months. For example, leaving THB 50,000 in withholding tax unpaid for 12 months would result in THB 9,000 in surcharges alone.
Additional penalties may also apply. If tax officials issue a summons and find that no return was filed, or that too little tax was paid, the company must also pay a fine equal to the tax due, or double that amount, depending on the case. Our THB 50,000 can then turn into THB 109,000, or THB 159,000.
VAT registration is another common source of penalties. A business must register for VAT within 30 days of its income passing THB 1.8 million a year. Companies that grow quickly sometimes cross that line without noticing. Even if VAT was never charged to customers, the business can still be required to pay the amount owed, along with applicable surcharges.
Directors’ responsibilities for annual financial statements
Every Thai Limited Company must hold an Annual General Meeting to approve its financial statements, then file them with the Department of Business Development (DBD) within one month of that meeting. Many foreign directors leave this entirely to their accountant. Directors nevertheless remain personally liable.
A company that fails to hold its AGM can be fined up to THB 20,000, and each of its directors up to THB 50,000. Repeated failures to file can eventually lead to a company being struck off the register. In August 2026, the DBD announced it was preparing to remove 11,234 Bangkok companies from the register, including 8,446 that had not filed financial statements for three consecutive years. A company in that situation loses its legal status and can no longer carry out legal transactions. However, outstanding liabilities may still be enforceable against directors and shareholders, depending on the circumstances
Social security and work permit penalties
Social security contributions must reach the Social Security Office by the 15th of the month after salaries are paid. That payment covers both the employer’s share and the amount deducted from each employee’s pay. If it arrives late, the employer owes an extra 2% per month. Since January 2026, contributions are capped at THB 875 per employee each month on each side. For a company with five employees earning above the ceiling, the monthly contribution comes to THB 8,750. Pay six months late, and the surcharge adds another 12%. Employees are affected too, the money has been taken from their salary, yet their social security rights may not be up to date.
Work permit violations carry substantially higher penalties. Employing a foreigner without a valid work permit or letting them work outside the scope of their permit, costs the employer THB 10,000 to 100,000 per foreign worker. A repeat offence can lead to up to one year in prison, fines of THB 50,000 to 200,000 per worker, and a three-year ban on hiring foreigners. The employee faces a fine of THB 5,000 to 50,000, deportation and a two-year ban on applying for a new work permit. Working outside the scope of a permit is treated the same way as working without one.
Tighter controls on foreign-owned businesses in 2026
Thai authorities have increased their scrutiny of nominee shareholder arrangements in 2026. In May 2026, the government said it had identified 6,551 foreign-controlled companies that may be operating restricted businesses without authorisation. The Prime Minister’s office summed up the policy as “no clearance, strict action on all cases.”
Penalties under the Foreign Business Act include up to three years in prison and fines of THB 100,000 to 1,000,000, plus daily fines of THB 10,000 to 50,000 for as long as the violation continues. The Thai nominee can be prosecuted, and so can anyone who knowingly took part.
The DBD has also introduced additional requirements for company registration. Since 1 April 2026, the DBD requires company registrants to sign a declaration confirming that all shareholders have genuinely invested. Giving false information to officials can lead to up to three years in prison. If your company relies on Thai nominee shareholders who have not genuinely invested in the business, it may face significant legal risks and increased scrutiny from Thai authorities. There is no simple solution to such arrangements, and businesses that have used nominee structures remain exposed to potential penalties. Our article, Thailand: Do You Really Need a Local Partner?, explains the legal framework and the importance of choosing a compliant ownership structure.
The Additional Costs of Non-Compliance
Late filings also create extra accounting and administrative work. Businesses that fall behind on their accounting and tax obligations often face additional administrative expenses. When a company falls behind, its accountant may need to go through months of bank statements and invoices, rebuild the accounts and prepare all the missing tax returns. Reconstructing several months of accounts takes time and increases accounting fees.
Business owners may also need to spend time dealing with the Revenue Department or the DBD, gathering documents and resolving outstanding issues. It can also take business owners away from their day-to-day operations.
Why Staying Compliant Costs Less
For a small service company in Thailand, monthly accounting and tax compliance typically costs around THB 5,000 to 10,000, as outlined in our previous article. Keeping your accounts up to date and filing on time helps avoid penalties and the extra work involved in correcting past mistakes.
If your business has outstanding filings or you are unsure whether your compliance obligations are up to date, contact Gorioux Siam. Our teams in Bangkok, Pattaya and Phuket can review your situation and assist with accounting, tax filings and ongoing compliance in English, French or Thai.