What is the time limit for appeal?

There are three primary deadlines: 15 days for an internal administrative appeal (from receipt of the order), 30 days for a tax assessment appeal under the Revenue Code (from receipt of the assessment), and 90 days for filing judicial review with the Administrative Court (from the agency’s decision or expiry of its response period). All three are strict jurisdictional deadlines.

Which court handles administrative disputes in Thailand?

The Administrative Court of Thailand hears disputes arising from government administrative actions. The system comprises the Administrative Court of First Instance (with regional divisions) and the Supreme Administrative Court, which serves as the final appellate body. These courts are entirely separate from the civil and criminal court system.

What is the Administrative Procedure Act Thailand?

The Administrative Procedure Act B.E. 2539 (1996) is the foundational statute governing how Thai government agencies must issue administrative orders, conduct hearings, and allow affected parties to file internal appeals. It establishes the 15‑day internal appeal deadline and sets minimum procedural fairness standards for administrative decision‑making.

How much does it cost to file an administrative case in Thailand?

Government filing fees for petitions at the Administrative Court are relatively modest, typically ranging from several hundred to a few thousand baht. However, the total cost of contested administrative litigation, including legal counsel, expert evidence, and document preparation, can be substantial. Each party generally bears its own costs unless the court orders otherwise.

Can I file for interim relief before the internal appeal has run its course?

In exceptional circumstances, yes. The Administrative Court may grant interim relief, including suspension of the administrative order, where the applicant demonstrates urgency, a risk of irreparable harm, a prima facie case on the merits, and that the balance of convenience favours suspension. Bypassing internal remedies requires specific justification documented in the petition.

What is Section 66/11 and when is it used?

Section 66/11 of the Act Establishing Administrative Courts codifies the grounds for judicial review. It permits challenges based on illegality (acting without authority), abuse of discretionary power, procedural unfairness or breach of natural justice, and failure to perform a legal duty. It is the statutory foundation for every administrative court petition in Thailand.

How do I calculate the 15‑day and 30‑day deadlines?

Both deadlines begin on the day after the date of actual receipt of the order or assessment. If the final day falls on a weekend or public holiday, it extends to the next business day. The date of receipt is determined by the delivery record, registered post receipt, agency delivery log, or electronic acknowledgement. Retaining proof of the receipt date is essential.

Administrative Litigation And Appeal In Thailand

Administrative litigation and appeal in Thailand operates under some of the tightest statutory deadlines in the Asia‑Pacific region, and missing even one of them can permanently extinguish a valid claim. Three numbers dominate every practitioner’s calendar: 15 days for an internal administrative appeal, 30 days for a tax assessment appeal under the Revenue Code, and 90 days for filing a petition for judicial review with the Administrative Court. As the volume of business and regulatory disputes channelled through Thailand’s administrative system continues to grow, understanding these deadlines, and the precise steps required to meet each one, has become essential for in‑house counsel, compliance teams, and litigators operating in the country.

This guide consolidates every critical timeline, procedural requirement, and strategic consideration into a single practitioner resource.

At a Glance, the 15 / 30 / 90‑Day Rules for Administrative Appeals in Thailand

Before examining each route in detail, the three core deadlines that govern administrative litigation and appeal in Thailand can be stated simply:

15 days from receipt of the administrative order, the window to file an internal (administrative) appeal with the issuing agency under the Administrative Procedure Act B.E. 2539 (1996).
30 days from receipt of the tax assessment notice, the deadline to lodge an objection or appeal with the Director‑General of the Revenue Department under Sections 28–37 of the Revenue Code.
90 days from the date the administrative body notifies its decision (or from the expiry of the period within which it should have responded), the time limit for filing a petition for judicial review with the Administrative Court of Thailand.

Every one of these deadlines is jurisdictional, not merely procedural, meaning that a late filing will typically be dismissed outright, regardless of merit.

Act now, immediate steps to preserve your rights:

Date‑stamp every document the moment it arrives; record the precise date of receipt.
Preserve the original envelope or delivery record as evidence of the trigger date.
Send all responses and appeals by registered post with acknowledgement of receipt.
Begin gathering documentary evidence and identifying witnesses immediately, do not wait until the appeal is drafted.

Legal Framework, Courts and Statutes That Matter

Thailand’s administrative appeal system is governed by an interlocking set of statutes and regulations. Understanding which law applies to a given dispute determines the correct deadline, the correct forum, and the correct procedure. The Administrative Procedure Act Thailand (APA) B.E. 2539 provides the foundational rules for how government agencies must issue administrative orders and how affected parties may challenge them internally. The Act Establishing Administrative Courts and Administrative Court Procedure B.E. 2542 (1999) then creates the judicial review pathway and sets out the powers and jurisdiction of the Administrative Court system. For tax disputes specifically, the Revenue Code contains its own appeal mechanism that operates alongside, but separately from, the general administrative framework.

Administrative Court System, Who Hears What

Thailand operates a two‑tier administrative court system. The Administrative Court of First Instance (with regional divisions across the country) hears initial petitions for judicial review of administrative actions, orders, and omissions. Appeals from that court proceed to the Supreme Administrative Court, which functions as the final appellate body. The Supreme Administrative Court also has original jurisdiction over certain categories of dispute, including those involving Royal Decrees and actions of independent constitutional bodies. Importantly, administrative courts are entirely separate from the civil and criminal court system, a petition filed in the wrong forum will be rejected.

Key Statutes and Regulations

Administrative Procedure Act B.E. 2539 (1996), governs internal appeal procedures, including the 15‑day time limit for challenging administrative orders within the issuing agency.
Act Establishing Administrative Courts and Administrative Court Procedure B.E. 2542 (1999), establishes the Administrative Court of Thailand, defines its jurisdiction, and sets the 90‑day judicial review filing deadline.
Revenue Code, Sections 28–37, provides the specific 30‑day appeal route for tax assessments, including requirements for payment or guarantee of disputed amounts.
Procedural notifications issued by the Administrative Court, official practice directions that specify evidentiary requirements, service rules, and hearing procedures.

Internal Administrative Appeal in Thailand: The 15‑Day Rule, Step by Step

The most commonly encountered, and most frequently missed, deadline is the 15‑day internal administrative appeal. Under the Administrative Procedure Act, when a government agency issues an administrative order that adversely affects a person (including a legal entity), the affected party has the right to appeal that order to a superior within the same agency. The 15‑day clock begins running from the date the affected party receives the order, not the date the order was issued.

This internal appeal applies broadly. It covers licence revocations, permit refusals, regulatory fines, orders to cease business operations, building demolition orders, environmental compliance directives, and many other administrative actions. The appeal must be in writing, must identify the specific order being challenged, and must state the factual and legal grounds on which the appeal is based. Generic or vague objections are routinely dismissed at the agency level.

The process itself follows a two‑stage structure. The affected party files its appeal with the agency that issued the order, addressed to the next superior officer or the designated appeal committee. That body then reviews the appeal, which may involve requesting additional documents or holding an oral hearing, and issues a decision, either confirming, modifying, or revoking the original order. If the agency rejects the appeal (or fails to respond within a reasonable period), the affected party can then escalate to judicial review before the Administrative Court.

What the appeal letter should contain:

Full identification of the appellant (name, address, registration number for legal entities).
Reference number and date of the administrative order being challenged.
A clear statement that the letter constitutes a formal appeal under the Administrative Procedure Act.
Specific factual grounds, what the agency got wrong, supported by documentary evidence.
Specific legal grounds, which provisions of law were misapplied or violated.
The relief sought (revocation, modification, or suspension of the order).
Date and signature of the authorised representative.

Counting the 15 Days, Receipt Rules and Practical Tips

The 15‑day period is calculated from the date of actual receipt. If the order is delivered by registered post, the date on the return receipt card is the trigger date. If delivered in person, the date recorded on the agency’s delivery log controls. Practitioners should insist on obtaining a copy of the delivery record immediately. Where the final day of the 15‑day period falls on a weekend or public holiday, the deadline extends to the next business day. Industry observers note that disputes over the trigger date are among the most common grounds for preliminary objections at the judicial review stage, meticulous record‑keeping at the outset can prevent a costly procedural defeat later.

Sample Internal Appeal Letter

A properly structured internal appeal letter follows a standardised format that addresses the agency, identifies the order under challenge, and sets out factual and legal arguments in numbered paragraphs. The letter should be filed in both Thai and (where the appellant is a foreign entity) in English translation. It is critical that the letter is filed within the 15‑day window and that proof of filing, whether a stamped receipt from the agency or a registered post acknowledgement, is retained. Practitioners working with foreign clients should begin drafting the appeal immediately upon receipt of the order to allow adequate time for translation and notarisation.

Tax Assessment Appeals in Thailand: The 30‑Day Route

Tax assessment disputes follow a distinct procedural track under the Revenue Code. When the Revenue Department issues a tax assessment notice, whether for income tax, value‑added tax, specific business tax, or stamp duty, the taxpayer has 30 days from the date of receipt of the assessment to lodge a formal objection. This deadline is set out in Sections 28–37 of the Revenue Code and is strictly enforced.

The objection is filed with the Director‑General of the Revenue Department (or, in practice, with the relevant Area Revenue Office that issued the assessment). The taxpayer must specify in writing the grounds for objection, identify the specific assessment being challenged, and provide supporting evidence. In many cases, the Revenue Department will also require the taxpayer to pay the assessed amount, or to provide a bank guarantee or other security for the disputed sum, before the objection will be processed. Failure to provide the required payment or guarantee can result in the objection being treated as abandoned.

Once the objection is filed, the Revenue Department conducts an administrative review. This process can take several months and may involve requests for additional documentation, site inspections, or meetings with the taxpayer’s representatives. At the conclusion of the review, the Director‑General issues a decision either upholding, reducing, or cancelling the assessment. If the taxpayer is dissatisfied with the outcome, the next step is to file a case with the Tax Court (a division of the civil court system) or, where the dispute involves an administrative action rather than a pure tax liability question, with the Administrative Court.

When the 30‑Day Deadline Applies vs. Other Tax Procedures

The 30‑day rule applies specifically to formal tax assessments issued under the Revenue Code. It does not cover voluntary tax filings, requests for refunds (which have their own separate timelines), or customs duty disputes (governed by the Customs Act). Practitioners must identify the precise legal basis of the assessment notice to confirm that the Revenue Code appeal route, and its 30‑day deadline, is the correct procedure.

Strategic Options, Administrative Review vs. Formal Objection

Before filing a formal objection, practitioners should consider whether informal engagement with the assessing officer may resolve the dispute more efficiently. In some cases, a request for reconsideration or clarification, made before the formal objection deadline, can lead to a revised assessment without the need for a contested proceeding. However, any informal engagement must not be allowed to consume the 30‑day window. The safest approach is to file the formal objection within deadline while simultaneously pursuing informal resolution.

Judicial Review and Section 66/11: The 90‑Day Rule and Grounds for Administrative Court Appeal

When internal remedies have been exhausted, or where no internal appeal route exists, the affected party may seek judicial review before the Administrative Court of Thailand. The time limit for appeal in this context is 90 days. The trigger event for the 90‑day period depends on the circumstances: it runs from the date the administrative body notifies its decision on the internal appeal, or, where the body fails to respond to a written request within the prescribed period, from the date that response period expires.

This distinction is critical. If an affected party sends a written request to an administrative body demanding that it act or reverse an order, and the body fails to respond within the time allowed by law, the 90‑day judicial review clock starts running automatically from the expiry of that response period. Practitioners who wait indefinitely for a response without tracking the statutory deadline risk forfeiting their right to judicial review entirely.

The grounds for judicial review are codified under Section 66/11 of the Act Establishing Administrative Courts. A petition may be brought where:

Illegality, the administrative body acted without legal authority, exceeded its jurisdiction, or applied the wrong legal provision.
Abuse of discretionary power, the body exercised its discretion for an improper purpose, in bad faith, or in a manner disproportionate to the objectives of the governing statute.
Procedural unfairness or breach of natural justice, the affected party was not given a fair opportunity to be heard, was not notified of the charges or reasons, or the decision‑maker was biased.
Failure to act, the administrative body had a legal duty to act and unreasonably failed or refused to do so.

The petition itself must set out the facts, identify the administrative action under challenge, specify the legal grounds relied upon, and state the relief sought (quashing the order, requiring the body to act, or awarding compensation). Poorly drafted petitions that fail to tie facts to specific legal grounds are vulnerable to preliminary dismissal.

Evidence Standard and Remedies Available

The Administrative Court operates under an inquisitorial system rather than the adversarial model used in civil courts. The court has the power to order production of documents, summon witnesses, and conduct its own investigation. The burden of proof generally falls on the administrative body to demonstrate that its action was lawful, proportionate, and procedurally fair.

Available remedies include quashing or annulling the administrative order, requiring the agency to perform a specific act, ordering payment of compensation for loss suffered as a result of an unlawful administrative action, and, in urgent cases, granting interim injunctions to suspend the effect of the order pending final determination. Industry observers note that interim relief is granted sparingly, typically only where the applicant can demonstrate a prima facie case on the merits, a risk of irreparable harm, and that the balance of convenience favours suspension.

Exceptions, Interim Relief, and Urgent Paths

While the general rule requires exhaustion of internal remedies before filing for judicial review, Thai law recognises exceptions. Where the internal appeal mechanism is clearly inadequate, where the administrative body has already demonstrated that it will not change its position, or where the urgency of the situation makes internal appeal impractical, the Administrative Court may accept a petition without prior exhaustion. These exceptions are narrowly construed, and practitioners should document the reasons for bypassing internal remedies in the petition itself.

Interim relief is available from the Administrative Court in cases involving urgency and irreparable harm. The court can order suspension of the administrative action, injunctions prohibiting further enforcement, and preservation of evidence. Applications for interim measures may be filed alongside the main petition or separately in cases of extreme urgency.

Checklist for Emergency Filings

Identify the specific administrative action causing immediate harm and quantify the irreparable damage.
Prepare a sworn statement of urgency explaining why normal timelines are inadequate.
Gather all documentary evidence of harm, financial statements, photographs, correspondence, expert opinions.
Draft the interim relief application specifying the exact order sought (suspension, injunction, preservation).
File the application with the Administrative Court of First Instance having territorial jurisdiction.
Serve copies on the respondent administrative body simultaneously.
Attend the court’s expedited hearing, typically scheduled within days of filing.

Practical Checklist and Timeline Matrix for Administrative Litigation and Appeal in Thailand

The following comparison table consolidates the three principal appeal routes, their deadlines, and the key practical steps that must be taken within each window. This matrix serves as a rapid‑reference tool for compliance teams and practitioners managing multiple administrative proceedings simultaneously.

Appeal Route	Deadline	Key Actions Within Deadline
Internal administrative appeal (most agencies)	15 days from receipt of order	Date‑stamp all correspondence; file written appeal to the issuing authority addressed to the next superior officer; clearly state factual and legal grounds; request internal review; preserve all documents and evidence
Tax assessment appeal (Revenue Code, Sections 28–37)	30 days from receipt of assessment	Lodge formal written objection with the Director‑General of the Revenue Department; pay the assessed amount or provide a bank guarantee if required; preserve the complete audit file and all supporting documentation
Judicial review (Administrative Court)	90 days from the date the administrative body notifies its decision or from the expiry of the body’s response period	Send a written request to the administrative body (if not already done); if the body issues an adverse decision or fails to respond, file a petition for judicial review with the Administrative Court; seek interim relief if the matter is urgent

Practitioner action prompts:

Create a centralised deadline‑tracking system that flags the 15 / 30 / 90‑day windows automatically upon receipt of any administrative order or assessment.
Assign a single point of contact within the legal team to manage receipt records and filing acknowledgements.
Retain certified copies of every filing, along with proof of postage or delivery, in a dedicated case file.
Where multiple deadlines overlap (for example, a tax assessment that also involves a regulatory order), file parallel appeals under both the Revenue Code and the APA to preserve rights under each regime.

Costs, Likely Timeline to Resolution, and Practical Expectations

Administrative litigation in Thailand involves several categories of cost. At the internal appeal stage, there is generally no government filing fee, the appellant bears only the costs of preparing and delivering the appeal documentation. At the Administrative Court level, filing fees are modest by international standards, typically ranging from a few hundred to a few thousand baht depending on the nature of the relief sought. However, the significant costs in contested proceedings are legal fees (counsel, expert witnesses, document preparation) and the opportunity cost of management time.

In terms of duration, internal administrative appeals are typically resolved within two to six months, depending on the complexity of the case and the responsiveness of the agency. Judicial review proceedings before the Administrative Court of First Instance generally take between one and three years from filing to final judgment. Appeals to the Supreme Administrative Court may add a further one to two years. Early indications suggest that recent court efficiency initiatives and new timeframe regulations may reduce these durations, but contested cases involving substantial evidence still require patience and sustained engagement.

Sample Case Flow, From Agency Order to Supreme Administrative Court

A typical administrative dispute follows a predictable escalation path. Understanding this flow helps practitioners plan resources and set client expectations from the outset:

Agency issues administrative order, the affected party receives a written decision (licence revocation, fine, tax assessment, or similar).
Internal appeal (15 days), the affected party files a written appeal with the issuing agency’s superior officer or appeal committee.
Agency decision on internal appeal (typically 2–6 months), the agency confirms, modifies, or revokes the original order.
Judicial review petition (90 days from agency decision or expiry of response period), if the internal appeal is unsuccessful, the affected party files a petition with the Administrative Court of First Instance.
Administrative Court proceedings (1–3 years), the court conducts its investigation, holds hearings, and issues a judgment.
Appeal to Supreme Administrative Court (if applicable), either party may appeal the first‑instance judgment on questions of law or procedure.

At each stage, the affected party must track deadlines meticulously, preserve evidence, and maintain complete records of all filings and communications. A single missed deadline can render the strongest substantive case unrecoverable.

Conclusion

The 15 / 30 / 90‑day framework that governs administrative litigation and appeal in Thailand leaves no margin for delay. Every day that passes after receipt of an administrative order or tax assessment brings a practitioner closer to an irrecoverable jurisdictional bar. The practical imperative is clear: date‑stamp immediately, preserve all evidence, and file within the applicable deadline, then prepare for the next stage. For complex disputes, early engagement with a specialist in Thai administrative law is not merely advisable but essential. Find an administrative law specialist through the Global Law Experts directory to ensure that your rights are preserved at every stage of the process.

Need Legal Advice?

This article was produced by Global Law Experts. For specialist advice on this topic, contact Jirawat Leelawanich at JIRAWAT & ASSOCIATES LAW OFFICE, a member of the Global Law Experts network.