Thailand introduced major tax changes in 2024, affecting how foreign sourced income sent from overseas is taxed. If you are a foreigner living in Thailand, understanding your tax responsibilities is now more important than ever. Filing your tax return correctly will help you avoid penalties and ensure you do not overpay.
This guide explains key tax deadlines, who needs to file, recent tax rule changes, and how to complete your tax return in Thailand.
Key Tax Deadlines for 2025
The Thai tax year runs from 1 January to 31 December. After the year ends, you must file your Personal Income Tax (PIT) return within the following deadlines:
- Paper filing: Submit your tax return at the Revenue Department office by 31 March 2025.
- E-filing: File online via the Thai Revenue Department’s website by 9 April 2025.
If you miss these deadlines, you could face late filing penalties or additional interest on unpaid tax.
Which Foreigners Need to File a Tax Return in Thailand?
Your tax filing obligations depend on your residency status and income sources.
Tax Residents
You are a tax resident of Thailand if you spend 180 days or more in the country in a calendar year. Tax residents must declare:
- All income earned in Thailand.
- Any assessable foreign income remitted to Thailand
Non-Tax Residents
If you spend fewer than 180 days in Thailand but earn income from Thai sources, you must still file a tax return and pay tax on Thai-sourced income (e.g. business profits, rental income, or salary from a Thai employer).
Do You Need to File a Thai Tax Return?
Not sure whether you need to file a tax return in Thailand?
Your tax obligations depend on factors like residency status, income sources, and whether you have remitted foreign income to Thailand.
To make things simple, we have created an interactive tool that helps you determine if you need to file a return. Answer a few quick questions, and we’ll guide you through your next steps.
If you are still uncertain or have a complex financial situation, our expert team can provide personalised advice.
New Foreign Income Tax Rule (Effective 2024)
Thailand’s new tax rule affects how foreign income is taxed.
Pre-2024 Income (Not Taxable)
Money earned before 1 January 2024 remains non-taxable in Thailand, even if you transfer it into Thailand in 2025 or later.
Post-2024 Income (Taxable if Remitted)
Foreign income earned from 1 January 2024 onwards is taxable if you bring it into Thailand in the same tax year it was earned. This change closes a previous loophole that allowed foreigners to delay transferring income to avoid Thai tax.
Double Tax Agreements (DTAs) & Avoiding Double Taxation
Thailand has Double Tax Agreements (DTAs) with 61 countries to prevent double taxation. These agreements may allow you to offset tax paid overseas against Thai tax liability.
How DTAs Work
- If you pay tax on your income in your home country, you may be able to claim a credit in Thailand to reduce your Thai tax bill.
- Some DTAs exempt certain types of income from Thai tax.
Check whether your home country has a DTA with Thailand and how it applies to your situation.
What Income is Taxable?
Taxable Income
If you are a tax resident, you must declare all taxable income remitted (transferred) to Thailand, including:
- Salary and employment income
- Business income
- Rental income from Thai property
- Pensions (except certain foreign state pensions)
- Dividends and capital gains
- Foreign income remitted to Thailand in the same tax year
Non-Taxable Income (Common Exemptions)
- Some excluded foreign pensions: Some foreign pensions are excluded through existing DTAs, such as US Social Security, Canadian pensions and overseas civil service pensions. We recommend looking at any appropriate DTAs to check whether there is an exclusion in place.
- Unremitted Overseas Income: Income not brought into Thailand is generally not assessable for tax.
Thailand’s Personal Income Tax Rates (2025)
Thailand has a progressive income tax system. The tax rate you pay depends on your total income:
How to File Your Tax Return in Thailand
You can file your tax return in person or online.
1. Obtain a Thai Tax Identification Number (TIN)
Before filing, you need a Tax Identification Number (TIN) from the Revenue Department. Without a TIN, you cannot submit a tax return.
You can obtain from your local revenue office, or if you need help with this, we have an easy to use, online TIN application service.
2. Choose Your Filing Method
- In-Person Filing: Submit your tax return at your local Revenue Department office.
- Online Filing: Use the Thai Revenue Department’s e-filing portal. English translations are available, but the system can be difficult to navigate for complex tax situations.
- Use a filing expert to file on your behalf: Expat tax Thailand’s core service is tax filing for expats for all situations here in Thailand with our online client portal. You fill out your details on a simple and easy to follow process, upload your documents and that is it!
Learn About Our Tax Filing Services Here
3. If filing yourself and not through our client portal
- Use the correct forms (PND.90, PND.91 or PND.94).
- Report your income accurately.
- Claim any eligible tax credits or deductions.
4. Pay Any Taxes Owed
You can pay your tax bill via:
- Bank transfer
- Online payment
- Direct payment at a Revenue Department office
5. Keep Records
Retain copies of your tax return and payment receipts for at least 5 years.
Tax Penalties for Late or Incorrect Filings
Late Filing Penalties
- Failure to file on time: THB 2,000 fine
- Late tax payments: Interest charged at 1.5% per month on unpaid tax
- Visa Renewal questions and queries: If you have an obligation to file, you could be asked for your tax certificate on your Visa renewal which if not provided may affect your Visa status
Incorrect or Fraudulent Tax Returns
In cases where the revenue investigate people who haven’t filed, or filed fraudulently, like all revenue departments, the penalties are very harsh.
They can include:
- Negligence can lead to additional fines. Up to 200% of the tax that is owed, plus a fine up to THB200,000.
- Deliberate tax evasion may result in civil or criminal penalties. From 3 months to 7 years in prison.
Stress-Free Tax Filing
If you’re finding the tax filing process overwhelming, our expat tax filing services are here to make it simple and stress-free. Whether you require assistance with a basic tax return or have a more complex financial situation involving multiple income sources, our expert team provides clear, tailored guidance to meet your needs.
We ensure your tax return is accurate, compliant, and optimised, helping you maximise deductions and claim any eligible tax credits to reduce your liability. With our support, you can easily avoid common filing mistakes, meet deadlines, and stay compliant with Thai tax laws. Let us take care of the complexities, so you can focus on enjoying life in Thailand. You can sign up here or click below to explore our service.
Need More Support?
Understanding your tax obligations is crucial given recent tax rule changes. If you are unsure about any part of the process, our support team can help.
