*Information current as of: September 19, 2026*
Thailand’s Revenue Department announced on September 15, 2026 that Thailand has signed the global minimum tax information exchange agreement. The most important point to clarify first: what this agreement exchanges is the filing data submitted by large multinational corporate groups that meet a revenue threshold. It is not aimed at everyone who sets up a company in Thailand, and it is not aimed at ordinary foreign residents.
Whether a business might fall under this regime is judged mainly by the consolidated revenue of the entire group. If, in at least two of the four accounting periods before the relevant accounting period, the group’s annual consolidated revenue reached EUR 750 million, it may meet the threshold. This applies to foreign corporate groups operating in Thailand as well as Thai corporate groups investing overseas.
If you’re living long-term in Thailand as an individual, buying property, or remitting foreign income into Thailand, this agreement does not affect you. It does not add any new personal tax, filing requirement, or data-provision obligation, and it does not change the existing personal income tax rules. Whether an individual’s income is taxable continues to be determined under the existing rules.
If you run a business in Thailand, the first step isn’t to immediately study how the global minimum tax is calculated, but to first confirm whether your company belongs to a multinational group that meets the threshold. An independent small business run by a foreign entrepreneur in Thailand does not automatically fall under this regime just because its shareholders are foreign, or because it has overseas clients. What actually needs to prepare related data is a multinational group that meets the threshold, and its related entities.
What Information Is Actually Being Exchanged?
The full name of this agreement is the Multilateral Competent Authority Agreement on the Exchange of GloBE Information. Thailand’s announcement calls it the GloBE MCAA; the OECD’s list of signatories calls it the GIR MCAA.
What it handles is the global minimum tax information return, known as the GloBE Information Return, or GIR. This return provides tax authorities with the data they need to assess risk and to reconcile top-up tax liability that different members of a multinational group may owe.
Think of it this way: a large multinational group may operate in multiple countries at once, and each country’s tax authority needs information about the group. With an exchange mechanism in place, participating jurisdictions can exchange GIR data, so companies don’t have to submit exactly the same content repeatedly in multiple places. One purpose of this exchange mechanism, then, is to reduce the repeated filing burden on large multinationals.
For businesses, the practical questions to handle are which entity within the group is responsible for filing, what data the Thai company needs to provide to the group, and what other filing and notification requirements still apply locally in Thailand. It’s worth noting that reducing repeated filing doesn’t mean that signing the agreement automatically removes all local Thai procedures — companies still need to check their own local obligations.
Paying Tax and Exchanging Data Are Two Different Timelines
This part is easy to confuse. Thailand’s Emergency Decree on Top-up Tax already applies to accounting periods beginning on or after January 1, 2025. This starting point was set out by Thailand’s Revenue Department in its announcement of December 27, 2024, and reconfirmed in its announcement of December 30, 2025.
Separately, Thailand expects to exchange GIR data with partner jurisdictions for the first time by December 2027 at the latest. So, 2027 is when data exchange is expected to happen for the first time — it is not when the top-up tax starts to apply. Businesses should not assume they can wait until 2027 to deal with related tax matters simply because data exchange has not yet started.
| Timing | Confirmed development | How to understand it |
|---|---|---|
| Accounting periods beginning on or after January 1, 2025 | Top-up tax decree begins to apply | Businesses must judge based on their applicable accounting period |
| August 4, 2026 | Thailand signs the agreement | Signing date differs from the public announcement date |
| September 15, 2026 | Thailand’s Revenue Department announces the signing | This is when this news was published |
| Expected by December 2027 at the latest | First exchange of GIR data with partner jurisdictions | This is the data-exchange timing, not a delay to the tax obligation |
Businesses’ actual filing, notification, and payment deadlines still need to be confirmed based on the applicable rules and the company’s own accounting year.
Look at the Size of the Whole Group First, Then at the Effective Tax Rate
Thailand’s top-up tax regime mainly targets large multinational corporate groups operating in Thailand, including Thai groups investing overseas and foreign groups investing in Thailand. What matters is not one Thai company’s individual turnover, but the consolidated financial statements of the ultimate parent company.
Specifically, in the four accounting periods before the period being assessed, if at least two of those periods had annual consolidated revenue reaching EUR 750 million, the group may meet the threshold. This EUR 750 million is a group-level revenue threshold — it is not anyone’s total personal assets, it is not just the turnover of a Thai subsidiary, and it is not just how much one company in Thailand earned.
So, even a Thai company that isn’t large on its own may still need to determine whether it falls within scope, and what data and filing responsibilities it has, if it belongs to a multinational group that meets the threshold. Conversely, an independent small business is not treated as a group that meets this threshold just because it has a foreign shareholder or overseas clients.
For example, suppose a Thai company is not large in itself, but it belongs to a multinational group whose consolidated revenue meets the EUR 750 million threshold — this Thai company may still need to help the group prepare GIR data. Conversely, if a small company independently run by a foreigner in Thailand does not belong to a group that meets the threshold, it does not become subject to this regime just because its shareholders are foreign or it has overseas clients.
The OECD’s explanation of the global minimum tax uses 15% as the minimum effective tax rate, calculated per jurisdiction based on the group’s relevant income and tax. If the calculated effective tax rate is below that standard, a top-up tax is then calculated according to the rules. But this doesn’t mean you can simply multiply 15% by a company’s revenue.
The actual calculation also involves income adjustments, substance-based income exclusions, and potentially applicable safe-harbor rules. So you also can’t judge purely from a company’s headline tax rate whether it needs to pay top-up tax, or how much it should pay. This explanation covers how the system works — it is not a calculation of the actual tax owed by any specific company.
Which Businesses in Thailand Need to Act? Which Individuals Are Not Affected?
If you’re still not sure whether this concerns you, use the table below as a first check.
| Your situation | Relationship to this arrangement | What to clarify first |
|---|---|---|
| A Thai company under a large multinational group | May be involved in GIR data and top-up tax arrangements | Whether the group meets the threshold, which type of entity the company is, who files, and how the effective tax rate is calculated |
| Running a business or investing in property through a company | First confirm which group the company belongs to; whether the business or asset is property doesn’t by itself determine applicability | Whether the company is included in the group’s consolidated statements, and what local obligations apply in Thailand |
| An independent small business | Not automatically at the threshold just because it has a foreign shareholder | Whether a group relationship exists, and which revenue base to judge by; general corporate tax obligations still apply separately |
| An individual buying property, retiring, or living long-term in Thailand | Not affected by this agreement | Existing personal tax rules remain unchanged |
| An individual with foreign income, or remitting money into Thailand | Not affected by this agreement | Whether foreign income is taxable is still judged under existing personal income tax rules |
An individual’s foreign pension, rental income, and investment income fall under a separate set of personal income tax rules. Thailand’s Revenue Department’s guidance on individual taxation considers factors such as the source of income, the individual’s residence status, the year the income was earned, when it was remitted into Thailand, and whether a foreign tax credit can be claimed under a relevant tax treaty.
Signing the GIR agreement itself does not replace these existing determinations. This article is only clarifying the scope of the global minimum tax information exchange regime — it does not determine, case by case, whether any particular type of individual income is tax-exempt or taxable.
What Should Businesses in Thailand Do Next?
This development means large multinational businesses handling tax filings need more internal coordination between different group entities. Companies can start by organizing the group structure, consolidated group revenue, the applicable accounting period, and the internal division of filing responsibilities, and then have a tax advisor confirm the applicable calculation method and local Thai requirements.
If a company’s investment evaluation involves tax incentives or exemptions, these are two separate things to check separately: one is what tax incentive the company received; the other is how that incentive affects the group’s overall effective tax rate in Thailand. The two shouldn’t be treated as the same question.
For professionals helping businesses operate in Thailand, the first question to ask is whether this company is included in a multinational group’s consolidated financial statements, and whether the whole group meets the EUR 750 million revenue threshold. If you’re simply living in Thailand as an individual, buying property, or remitting foreign income, this agreement does not require you to prepare any additional data or make any new filing.
Frequently Asked Questions
Now that Thailand has joined the information exchange, will individuals’ foreign income be taxed at 15%?
No. This agreement does not affect the tax rules that apply to individuals living long-term in Thailand, buying property, or remitting foreign income, and it does not add any new personal filing obligation.
Thailand’s Revenue Department’s GloBE MCAA, announced on September 15, 2026, deals with the exchange of GIR data for large multinational corporations. The 15% figure referenced by the OECD is the minimum effective tax rate calculated per jurisdiction under the global minimum tax regime, and cannot be applied directly to an individual’s foreign pension, rental income, investment income, or remittances.
An individual’s tax situation still needs to be assessed based on factors such as tax residency status, source of income, the year the income was earned, remittance circumstances, and any applicable tax treaty. Likewise, not being subject to the corporate global minimum tax regime doesn’t mean a person necessarily has no other personal income tax liability — these are two separate determinations.
In practice, when organizing your information, separate personal income from company income first, confirm who earned the income and who holds the asset, and then explain the relevant years and remittance circumstances to a tax advisor. If the asset is held through a company, you’ll need to further confirm whether that company belongs to a group that meets the threshold. This article only distinguishes the scope of the regime — it does not make a tax-exempt or taxable determination on any specific personal income.
If a Thai company is small, does that mean it definitely isn’t subject to the global minimum tax?
Not necessarily, because you can’t judge based on a single Thai company’s own turnover alone. Under Thailand’s Revenue Department’s explanation of the top-up tax decree dated December 27, 2024, the revenue threshold is based on the ultimate parent company’s consolidated financial statements. You need to look at the four accounting periods before the period being assessed, and confirm whether at least two of those periods had annual revenue reaching EUR 750 million.
So, a smaller Thai subsidiary, if it belongs to a group that meets the threshold, still needs to determine whether it falls within scope, what data it needs to provide to the group, and which entity is responsible for filing. Conversely, an independent small business does not automatically meet this group threshold just because its shareholders are foreign or it has overseas clients.
For anyone running a business or investing in property through a company, the starting point for analysis is also the company and group structure. You can’t judge based only on whether the asset is property, the scale of the project, or a company’s headline tax rate. A company should first organize the relationships between its entities, its consolidated financial statements, and its accounting period, and then examine its effective tax rate and the applicable rules — that way, “whether it falls within the regime’s scope” and “how much tax is actually owed” can be handled as two separate questions. Even if a group meets the revenue threshold, that doesn’t mean the minimum rate can simply be multiplied by revenue to calculate the tax.
Data exchange is expected to happen for the first time in 2027 — can businesses wait until then to deal with it?
No, the timing of the first data exchange cannot be used to infer that businesses can delay handling their tax obligations. In its September 15, 2026 announcement, Thailand’s Revenue Department stated that Thailand expects to exchange GIR data with partner jurisdictions for the first time by December 2027 at the latest. However, Thailand’s top-up tax decree already applies to accounting periods beginning on or after January 1, 2025, which the Revenue Department reconfirmed again in its December 30, 2025 announcement.
Data exchange, corporate filing, notification, and tax payment are several distinct steps. Each step’s requirements need to be checked against the applicable rules and the company’s own accounting year. Companies can start now by confirming whether the relevant data should be prepared by group headquarters, a designated entity, or the local Thai company, and what calculation data and documentation the Thai company needs to provide.
One purpose of the information exchange mechanism is to reduce the burden on multinational groups of repeatedly submitting the same data in different places. However, the announcement does not promise that all local Thai procedures will be eliminated. For applicable businesses and the professionals who help them file, the expected first exchange in 2027 represents progress in international tax cooperation. Businesses still need to separately confirm their own filing and payment requirements, and should not conflate these different timelines.
Assessing a property purchase or business venture in Thailand?
If you’re not sure whether to deal with personal income tax, corporate tax, or the group top-up tax first, feel free to ask Zagdim. We can help you organize the questions and the research direction.
This article provides general information and policy interpretation and does not constitute tax, legal, or investment advice for any individual case.
Have a question about this guide? Leave a comment below, or ask Zagdim directly.
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Sources
- *Thailand Revenue Department – “Thailand Signs the GloBE MCAA”
- OECD – “Signatories of the GIR MCAA”
- Thailand Revenue Department – “Emergency Decree on Top-up Tax Officially Promulgated”
- OECD – “Global Minimum Tax”
- OECD – “Global Anti-Base Erosion Model Rules (Pillar Two) — GloBE Information Return”
- Thailand Revenue Department – “How Do Foreigners Living in Thailand Pay Tax?”
- Thailand Revenue Department – “Draft Secondary Legislation under the Emergency Decree on Top-up Tax”*
