What Happens If You File Taxes Late in Thailand? Penalties, Surcharges and Criminal Liability (Revenue Code)

In short

Filing late or underpaying tax in Thailand triggers three tiers of consequences: civil penalties (เบี้ยปรับ) — under VAT, failing to file on time costs a penalty of twice the tax payable; surcharges (เงินเพิ่ม) — under VAT, charged at 1.5% per month and capped at the amount of tax itself; and criminal liability — from fines of no more than 2,000 baht at the light end, up to three months to seven years of imprisonment for evading tax or claiming refunds by falsehood or fraud. Penalties can be reduced or waived under the Director-General's regulations — the earlier you voluntarily file the missing returns, the smaller the damage.

Three tiers of liability: penalties, surcharges, criminal sanctions

The Thai Revenue Code imposes an escalating system of liability for late filing, non-filing and underpayment. Understanding the difference between these three tiers is the first step in judging how serious your situation is.

Civil penalty เบี้ยปรับ

Calculated as a multiple of the tax: under VAT, failing to file on time carries a penalty of twice the tax payable for that tax month, while filing errors that cause underpayment carry a penalty of once the discrepant amountSection 89. Penalties may be reduced or waived under the Director-General's regulations.

Surcharge เงินเพิ่ม

The equivalent of late-payment interest: under VAT it accrues at 1.5% per month (a fraction of a month counts as a full month), running from the expiry of the filing deadline until the date of actual payment, but the total may not exceed the amount of tax payable itselfSection 89/1.

Criminal liability Fines and imprisonment

Simple lateness usually stops at a fine; but intentionally failing to file in order to evade tax is punishable by imprisonment of up to one year or a fine of up to 200,000 baht, or bothSection 37 bis, and evading tax or claiming a refund by falsehood or fraud is punishable by three months to seven years of imprisonment plus a fine of 2,000 to 200,000 bahtSection 37.

VAT: how penalties are calculated

VAT is filed monthly, and the penalty scenarios are listed item by item in Section 89. The most common include:

Operating without registering when registration is required: a penalty of twice the tax payable for each tax month during the period of operation, or 1,000 baht per tax month, whichever is higher.
Failing to file a tax return or remittance form within the deadline: a penalty of twice the tax payable or remittable for that tax month.
Filing errors that cause a discrepancy in the tax payable: a penalty of once the discrepant amount.
Misstating output tax or input tax in the return: a penalty of once the amount of output tax understated or input tax overstated.
Failing to issue and deliver a tax invoice when required: a penalty of twice the amount of tax on that invoice.
Issuing a tax invoice without the right to do so, or using a fake tax invoice for credit: a penalty of twice the amount of tax shown on the invoice; where the beneficiary cannot prove who issued the invoice, it is deemed to be a fake tax invoice.
Failing to keep tax invoices or their copies as required: a penalty of 2% of the tax on the invoice or of the tax credited.

The final paragraph of the same section makes clear that these penalties may be reduced or waived under regulations prescribed by the Director-General with the Minister's approvalSection 89. This is exactly where voluntary back-filing pays off — penalties are not set in stone, but relief only starts once you act.

VAT: surcharge of 1.5% per month, capped at the tax itself

Anyone who fails to pay or remit tax in full within the deadline pays a surcharge of 1.5% per month of the tax payable or remittable, with any fraction of a month counted as a full month; the calculation base is the tax itself, excluding penaltiesSection 89/1. The same section sets out three key details:

Start and end dates: the surcharge runs from the day the filing deadline expires until the date of actual payment or remittance.
Cap: the total surcharge cannot exceed the amount of tax payable or remittable itself — it does not roll up forever.
Reduced rate for approved extensions: where the Director-General approves an extension of the payment deadline and the tax is paid in full within the extended period, the surcharge drops to 0.75% per month.

In addition, for collection purposes the tax, penalties and surcharges are all treated as value added taxSection 89/2 — meaning unpaid penalties and surcharges go into enforced collection just like the tax itself.

VAT: tiered criminal sanctions

Beyond civil penalties, the VAT chapter carries its own separate set of criminal sanctions, tiered by severity:

Fine not exceeding 2,000 baht: covers procedural breaches such as a registered entrepreneur failing to file a return under Section 83Section 90.
Imprisonment of up to one month or a fine not exceeding 5,000 baht, or both: covers operating without VAT registration when registration is required, failing to issue and deliver a tax invoice to the buyer, and similar breachesSection 90/2.
Imprisonment of up to six months or a fine not exceeding 10,000 baht, or both: covers failing to prepare the required input-output tax reports, and obstructing or failing to facilitate an assessment official performing their dutiesSection 90/3.
Imprisonment of three months to seven years plus a fine of 2,000 to 200,000 baht: intentionally evading or attempting to evade VAT — issuing tax invoices without the right to do so, deliberately omitting or falsifying entries in the reports, deliberately not issuing invoices, evading tax or claiming refunds by falsehood or fraud, or intentionally using counterfeit or unlawfully issued tax invoices for creditSection 90/4.

⚠️ When the company is penalized, directors can face criminal liability too

Where a juristic person's offense arises from the order or act of a director, manager or other person responsible for its operations, or from that person's failure to act when under a duty to do so, that individual is subject to the same punishmentSection 90/5. The same personal liability applies in situations such as transferring or concealing attached property, with imprisonment of up to two years plus a fine of up to 200,000 bahtSection 35 bis. The corporate shell will not shield you from tax-related criminal liability.

Income tax: filing deadlines, assessments and additional charges

Direct taxes (personal and corporate income tax) carry their own penalty and surcharge mechanisms. The common checkpoints include:

Annual filing deadline: a company or juristic partnership must file the statements needed to calculate its tax and pay the tax within one hundred and fifty days of the end of the accounting periodSection 68.
Underestimated half-year prepayment: failing to file the half-year statement and prepay as required, or without reasonable cause underestimating projected net profit by more than 25% of actual net profit, triggers a surcharge of 20% of the tax payable or the shortfallSection 67 ter.
Deemed assessment for missing books or non-cooperation: where a company fails to file the statements needed for tax calculation, keeps no accounts, or does not produce its books and supporting documents to the assessment official, the official may assess tax outright at 5% of gross receipts or gross sales before any deduction of expenses, whichever is higher; where omissions or errors in the accounts cause underpayment, the official may assess the shortfall and order an additional payment of twice the deficient taxSection 71.
Procedural fines: failing to comply with the filing requirements of provisions such as Section 17 and Section 69 carries a fine not exceeding 2,000 baht, unless force majeure can be shownSection 35.
Payment deadline after assessment: where the assessment official assesses additional tax, it must be paid in full — together with penalties and surcharges — within thirty days of receiving the assessment noticeSection 18 ter.

Under the income tax provisions, the penalties under Sections 22 and 26 and the surcharge under Section 27 are expressly deemed to be tax, and may be reduced or waived under regulations prescribed by the Director-General with the Minister's approval and published in the Royal GazetteSection 27 bis; the exact penalty rates and extent of relief are as officially prescribed (our firm can help confirm).

The final consequences of non-payment: seizure, auction, and appeals that do not suspend enforcement

Tax unpaid past its due date becomes tax arrears. To collect arrears, the Director-General may — without any court order — order the attachment or garnishment and public auction of the taxpayer's property anywhere in the Kingdom; auction proceeds are applied to the arrears after deducting costs, with any remainder returned to the property owner. For partners with unlimited liability, collection extends to them personallySection 12. Once an attachment or garnishment order has been issued, no one may destroy, remove, conceal or transfer the property concerned to another personSection 12 bis.

Another commonly misunderstood point: appealing an assessment or taking it to court does not waive or suspend the obligation to pay — tax unpaid by the deadline is still treated as arrears, unless the Director-General approves waiting for the outcome of the appeal; once the appeal decision or final judgment is issued, payment is due within thirty daysSection 31.

How to fix it: voluntary back-filing and seeking relief

If you discover overdue, missed or underpaid filings, the logic of the remedy is clear:

Penalties have a statutory relief channel: both VAT penalties and income tax penalties may be reduced or waived under the Director-General's regulationsSection 89Section 27 bis. Voluntary back-filing is the practical precondition for starting relief; the exact extent and conditions are set by the Director-General's regulations and are as officially prescribed (our firm can help confirm).
Surcharges accrue monthly — the earlier you file, the less you pay: the VAT surcharge adds 1.5% for every month of delay; although capped at the tax amount, running it to the cap means the bill doubles — the tax plus an equal surchargeSection 89/1.
If you have already received an assessment notice, watch the thirty-day deadline: missing it puts you into arrears enforcement, and an appeal does not suspend the obligation to paySection 18 terSection 31.
Never plug the hole with fake invoices or false filings: that pushes the problem straight from the penalty tier into the criminal tier of three months to seven years of imprisonmentSection 37Section 90/4.

Filing on time is the cheapest option

As the provisions above show, Thai tax law prices lateness exponentially: first penalties in multiples of the tax, then surcharges rolling up month by month, criminal liability as matters escalate, and ultimately even personal exposure for directors. By comparison, the cost of simply filing VAT, withholding tax and social security on time every month is close to negligible.

SLF Accounting provides monthly bookkeeping and filing services for businesses in Thailand: VAT, withholding tax and other returns filed and paid on schedule each month, with input-output figures and supporting documents reconciled before filing, so penalties and surcharges never arise in the first place. If you have already received an assessment notice from the Revenue Department or discovered gaps in past filings, we can also help assess which tier of liability you face, handle the back-filing, and follow up on applications for penalty relief.

FAQ

How much is the penalty for filing VAT late in Thailand?

Under Section 89 of the Revenue Code, failing to file a return within the deadline carries a penalty of twice the tax payable for that tax month; filing errors that cause underpayment carry a penalty of once the discrepant amount. On top of that, Section 89/1 adds a surcharge of 1.5% per month (a fraction of a month counts as a full month). Penalties may be reduced or waived under the Director-General's regulations, and voluntary back-filing is the precondition for seeking relief.

Does the surcharge keep accumulating forever?

No. Section 89/1 is explicit: the VAT surcharge is calculated at 1.5% per month of the tax payable, running from the expiry of the filing deadline until the date of actual payment, but the total cannot exceed the amount of tax payable itself; where the Director-General approves a payment extension and the tax is paid in full within the extended period, the rate drops to 0.75% per month.

Can you go to prison for late tax filing in Thailand?

It depends on the tier. Simple lateness usually stays at the fine level — for example, failing to file a VAT return under Section 83 carries a fine of no more than 2,000 baht (Section 90). But intentionally failing to file in order to evade tax carries up to one year of imprisonment or a fine of up to 200,000 baht, or both, under Section 37 bis; and evading tax or claiming a refund by falsehood or fraud carries three months to seven years of imprisonment plus a fine under Section 37 and Section 90/4.

If a company is penalized for tax offenses, are its directors personally liable?

Possibly. Section 90/5 provides that where a juristic person's offense arises from the order or act of a director, manager or person responsible for its operations, or from that person's failure to act when under a duty to do so, that individual is subject to the same punishment. In addition, where tax goes unpaid past the deadline, the Director-General may attach and auction property directly without a court order under Section 12, and transferring or concealing attached property carries separate criminal liability (Section 12 bis, Section 35 bis).