Thailand Plans to Follow Global Minimum Tax Rules from 2025

What’s Happening?
Thailand is changing its tax system to follow the Global Minimum Tax (GMT) rules made by the Organization for Economic Co-operation and Development (OECD)

What Is the Global Minimum Tax (GMT)?

Big multinational companies (those earning more than €750 million per year, must pay at least 15% tax in every country they operate in.

• This stops companies from shifting profits to countries with very low or zero tax rates just to save money.
• It makes the global tax system fairer, ensuring all countries get their fair share of tax revenue.
• Countries with very low taxes will no longer be able to attract companies only through cheap tax rates.
• The idea is supported by more than 140 countries under the OECD framework, making it a major global tax reform.

Overall, GMT creates a level playing field, so businesses compete based on real performance, not finding the lowest-tax country.

Top-Up Tax Will Be Collected

If a company pays less than 15% tax because of BOI benefits, Thailand will collect the extra amount to reach 15%.
Example: Company pays 3% tax, but Minimum required is 15% then Thailand will collect the remaining 12% as top-up tax.

BOI Incentives Will Change

Because tax holidays will not help big companies anymore, Thailand will give new non-tax benefits, such as:

• Cash support
• Training and skill development programs
• Innovation and R&D support
• Easier and faster work permits for foreign experts
• Quicker approvals for business operations

When Did This Start?

• 2019: Countries in the OECD and G20 began holding meetings to discuss the idea of a Global Minimum Tax.
• October 2021: More than 135 countries, including Thailand agreed that they would follow these new global tax rules.
• 7 March 2023: The Thai Cabinet approved the plan in principle, meaning they agreed to start preparing to do the Global Minimum Tax in Thailand.
• 2024: Several countries such as Japan, South Korea, and all European Union countries started applying the new tax rules.
• 2025: Thailand will officially implement and start using the Global Minimum Tax system.

What Will Change in Thailand After 1st January 2025?

Earlier, Thailand encouraged investors by giving tax holidays or tax exemptions through the Board of Investment (BOI).

• But under the new GMT rule, large multinational companies must still pay at least 15% tax, even if Thailand gives them tax benefits.
• Local businesses will benefit because big companies will no longer get unfair tax advantages over them.
• Thailand will become more aligned with global tax standards, improving its international reputation.
• It encourages multinational companies to have real operations in Thailand instead of only registering there for tax benefits.

But from 2025 onwards:

The old tax exemption system will be replaced by a Refundable Tax Credit system. Companies will still get tax benefits but in a more transparent and fair way, following the new international tax rules.

Why This Is Important

• It keeps Thailand competitive with other countries for foreign investment.
• It makes Thailand tax system fairer and transparent
• It helps Thailand maintain a good global reputation with investors.

How CSG Advisory Can Help You

It is tough for big international companies to understand Thailand's new tax laws. CSG Advisory helps them navigate these changes, making sure they follow the new 15% Global Minimum Tax rules while still getting the best benefits from the updated investment programs.

Understanding the new 15% Global Minimum Tax rules

BOI guidance under the new system

Business setup planning

Company registration in Thailand

VAT filings in Thailand

Opening bank account in Thailand

Accounting and tax filing services

Compliance support for multinational groups

This is the best chance to invest and start a company in Thailand.

Many experts are calling 2025–2026 the “Golden Era for Investment” in Thailand.