Tax Appeals & Litigation

Tax appeals and tax litigation
at every stage of the process

Q: I have received a notice of tax assessment. What should I do first?

The first step is to establish clearly the date on which you received the notice, because the 30-day period for filing an appeal runs from that date. Then gather all relevant documents, such as contracts, tax invoices, accounts, and supporting accounting records, and contact a tax law consultant promptly, because preparing a sound appeal takes time.

Disputing notices of tax assessment, appealing to the Commission of Appeal, and litigating in the Central Tax Court — by Eksiam Chaisorn, tax law consultant, with the firm's team of lawyers and legal consultants, handling every type of tax case.

Send us your assessment notice for a case assessment → See the appeal process →

Deadline under the Revenue Code

An appeal against a notice of tax assessment from the Revenue Department must be filed within 30 days of receipt (Revenue Code, Section 30). Once this period has passed, the right to dispute is lost and the tax must be paid as assessed, together with the penalty and surcharge.

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Contents

Every type of tax dispute
The four stages of a tax dispute
The legal cost of missing the deadline
Frequently asked questions

Every type of tax dispute

Categories of tax disputes we handle

We handle tax disputes and tax cases of every type, from disputing a notice of tax assessment to criminal tax cases, under the supervision of a tax law consultant working with the firm's team of lawyers and legal consultants.

Disputing a notice of tax assessment

Revenue Code, Section 30 · within 30 days

With a notice of tax assessment, the assessment official exercises the power to assess additional tax together with penalties and surcharges. The person liable to pay the tax has the right to dispute it by filing an appeal within 30 days.

Corporate income tax VAT Withholding tax Transfer Pricing

Appeals to the Commission of Appeal

Revenue Code, Section 30(2)

If you are not satisfied with the Commission's appeal decision, you may bring the case before the Central Tax Court within 30 days of being notified of the appeal decision.

Presenting evidence Legal argument Negotiation

Cases in the Central Tax Court

Tax Court Act B.E. 2528 (1985)

Court representation and litigation in the Central Tax Court, which has jurisdiction over every type of tax dispute — from filing the complaint and the taking of evidence to appeals against the judgment.

Filing the complaint Expert witness evidence Appeal and further appeal to the Supreme Court

Defending at the tax audit stage

Revenue Code, Sections 19–27

Setting the strategy and providing information during the assessment official's audit is the first and most important line of defense, because if the facts are fully explained at this stage, a notice of assessment may never be issued on that issue.

Gathering documentary evidence Explaining to the officials Negotiating penalty reductions

Claiming refunds of overpaid tax

Revenue Code, Section 27 ter · within 3 years

Filing claims for refunds of tax paid without liability or in excess of the amount payable, including action where the Revenue Department refuses a refund claim or delays unreasonably.

VAT Refund Withholding tax Corporate income tax

Criminal tax cases

Revenue Code, Sections 37, 37 bis, and 90/4

Advice and case handling where Revenue officials file a criminal complaint arising from false returns, tax evasion, or the issuance of fake tax invoices.

False returns Fake tax invoices Tax evasion

II.

The four stages of a tax dispute

The four-stage appeals process

Thailand's tax dispute process is divided by law into four stages. Each stage has its own time frame and strategy. Understanding the whole picture from the outset helps you preserve your rights and plan your course of action systematically.

Stage 1

Explaining at the audit stage

Revenue Code, Sections 19–23

The assessment official has the power to issue a summons requiring the taxpayer to give statements and produce documentary evidence. This stage is the first opportunity to explain the facts before any additional tax is assessed.

No fixed deadline — but the summons must be answered within the time it specifies

Stage 2

Disputing the notice of assessment

Revenue Code, Section 30

On receiving a notice of assessment, you may file an appeal with the Commission of Appeal within 30 days, attaching the evidence and your arguments of both fact and law.

Within 30 days of receipt of the notice — extendable only where the Director-General considers it appropriate under Section 3 octo

Stage 3

The Commission of Appeal

Revenue Code, Section 30(2)

The Commission considers the evidence and issues its decision. This process may take from several months to several years. If you are not satisfied with the appeal decision, you may bring proceedings in court.

Proceedings may be brought in court within 30 days of notification of the appeal decision

Stage 4

The Central Tax Court

Tax Court Act B.E. 2528 (1985)

The Central Tax Court has jurisdiction over every type of tax dispute, and cases at this stage are heard by judges who specialize in tax. Its judgments may be appealed to the Court of Appeal for Specialized Cases and further to the Supreme Court in accordance with the criteria prescribed by law.

An appeal against the judgment to the Court of Appeal for Specialized Cases must be filed within 1 month

III.

The legal cost of missing the deadline

What the law says about missing the deadline

The table below shows the legal consequences under the Revenue Code in two situations — an appeal filed within the deadline compared with a missed appeal deadline.

Item	Statutory rate	If you appeal within the deadline	If the appeal deadline is missed
Penalty for failure to file a return	Tax payable × 2	Can be disputed and reduced	Paid in full as assessed
Penalty for an incorrect return	Tax shortfall × 1	Can be disputed and reduced	Paid in full as assessed
Surcharge	1.5% per month of the tax payable	From the due date until the date of payment	Accrues up to, but not exceeding, the amount of tax payable (Section 27)
Right to dispute the facts	—	Full rights at every stage	Lost entirely
Deferral of tax payment	Requires the Director-General's approval (Section 31)	Can be requested together with the appeal	Not available; unpaid tax is deemed tax arrears

IV.

Frequently asked questions

Frequently asked questions on tax disputes

I have received a notice of tax assessment. What should I do first?

The first step is to establish clearly the date on which you received the notice, because the 30-day period for filing an appeal runs from that date. Then gather all relevant documents, such as contracts, tax invoices, accounts, and supporting accounting records, and contact a tax law consultant promptly, because preparing a sound appeal takes time.

I agree with part of the assessment but not the rest. Can I appeal only part of it?

Yes. The law allows an appeal limited to the disputed part. The appeal must state clearly which items are disputed, on what grounds, and by how much the tax should be reduced. A sound appeal combines arguments of fact and of law, supported by evidence.

Must I pay the assessed tax while the appeal is pending?

Yes, within the prescribed time, unless the Director-General approves waiting for the appeal decision or the court judgment, because Section 31 of the Revenue Code provides that an appeal is not a deferral of tax payment. If the tax is not paid within the time prescribed by law, it is deemed tax arrears under Section 12, and the surcharge of 1.5% per month runs until the date of payment but may not exceed the amount of tax payable (Section 27). An appellant should therefore consider filing a request for deferral of tax payment together with the appeal.

Can an additional transfer pricing assessment be challenged?

Yes. Transfer pricing cases are among the most complex tax cases, but they can be contested if there is evidence that the transfer prices used are consistent with the market price standard (the arm's length principle). Having complete TP documentation in place before the audit gives a much stronger basis for contesting the case.

Roughly how much does a tax case cost?

Fees depend on the complexity of the case and the amount in dispute. They are generally charged by the hour or as a fixed fee per case, as agreed, and are set out in a written engagement agreement before work begins. Contact us for a preliminary case assessment →

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The 30-day period is short

Seeking advice at an early stage helps preserve your rights and plan the conduct of the case systematically. We reply within the business day, and your information is kept strictly confidential.

+66 81 654 5922

Send us your assessment notice for a case assessment → View all tax dispute services

Tax appeals and tax litigationat every stage of the process