Filing personal income tax is a legal obligation for everyone who earns income in Thailand. If you earned income during the year 2025, you are required to file your personal income tax return in 2026.
This article explains everything you need to know — especially if this is your first time filing tax — in a simple, step-by-step way based on information from the Thai Revenue Department.
Who Must File Personal Income Tax?
You are required to file a personal income tax return if you earned any type of income in 2025, including:
Salary or wages
Freelance or professional fees
Business income
Commission, bonus, or allowance
Rental income
Interest or dividend income
Even if your income is below the taxable threshold, filing a return is still recommended to confirm your tax status and avoid future issues.
Which Tax Forms Should You Use?
There are two main personal income tax forms in Thailand:
P.N.D. 90
For individuals with income other than salary, such as freelancers, business owners, or multiple income sources.
P.N.D. 91
For individuals with salary income only.
Choosing the correct form is essential to ensure accurate tax calculation.
Documents You Need to Prepare
Before filing your tax return, prepare the following documents:
Income statements (e.g. Form 50 Tawi)
ID card number
Bank account details (for tax refund, if any)
Documents for tax deductions, such as:
Insurance premiums
Retirement funds
Donations
Home loan interest
Having complete documents helps reduce errors and speeds up the filing process.
How to File Your Tax Return Online (E-Filing)
The easiest and fastest way to file your tax return is through the Revenue Department’s e-Filing system:
Register or log in to the e-Filing system
Select the correct tax form (P.N.D. 90 or 91)
Enter your income and deductions
Review the tax calculation
Submit your tax return
Pay additional tax or wait for a refund (if applicable)
Online filing reduces paperwork and allows you to track your status easily.
Filing Deadline
Online filing: January – March 2026
Paper filing: January – March 2026
Late filing may result in penalties and surcharges, so it is best to file early.
Filing Tax for the First Time: What You Should Know
If this is your first time filing personal income tax, keep these tips in mind:
Register for e-Filing in advance
Double-check your income details
Keep copies of all documents
File even if no tax is payable
Filing correctly from the beginning helps build a good tax record for the future.
Official References (Thai Revenue Department)
For the most accurate and up-to-date information, please refer to the official website of the Thai Revenue Department:
Final Thoughts
Filing personal income tax may seem complicated at first, but with the right preparation and understanding, it becomes a straightforward process. Whether you are a salaried employee, freelancer, or business owner, filing your tax return correctly helps ensure compliance and financial transparency.