Filing your Thai tax online as a seller, step by step from login to submit (PND 90 and 94)

You know full well you have to file your tax, but the moment you open the Revenue Department website, you close it again because you have no idea where to start. And as a seller without the 50 Tawi withholding certificate (ใบ 50 ทวิ) that salaried employees get, it is even more confusing which boxes to fill in.

If you’re not sure yet whether you need to file at all, read Do online sellers have to pay tax? first. This page is purely practical. Open your computer or phone next to you and follow along step by step.

Note: The e-Filing screens are updated from time to time, so button names may differ slightly from what is written here, but the order of steps stays the same. This page is general information. If you get stuck anywhere, call the Revenue Department information center on 1161.

When do you file, and how many times a year?

Quick Answer: Twice a year. PND 94 for income in the first half of the year, filed July to September, and PND 90 for the full year’s income, filed January to March of the following year. Filing online gives you 8 extra days.

Form	Income period	Paper filing deadline	Online filing deadline
PND 94 (ภ.ง.ด.94)	January to June	September 30	October 8
PND 90 (ภ.ง.ด.90)	Full year	March 31 of the following year	April 8 of the following year

The next round to prepare for is PND 90 for 2026 income, which you can file from January 1, 2027. If the Revenue Department gives the usual 8 extra days for online filing, the deadline will be April 8, 2027, but check the announcement again at the start of the year.

If you’ve already missed this year’s PND 94, don’t worry. You can still file, and the sooner you do, the smaller the surcharge.

What to prepare before you open the website

Quick Answer: Have your total sales for the period ready, decide whether you’ll take the flat deduction or actual expenses, and gather proof for your allowances. Spend 30 minutes preparing and the actual filing takes 20 minutes.

Get these ready first:

• Your Thai ID card (you use the 13-digit number and the Laser ID code on the back when signing up), or the ThaID app on your phone
• Total sales from every channel: download the income reports from Shopee, Lazada and TikTok Shop, and add up what you sold through LINE or in person
• Total actual expenses, if you’ll deduct actual expenses, with receipts kept on file (you don’t attach them, but you must have them available for inspection)
• 50 Tawi certificates, if you have income that had tax withheld, such as review work or freelance work
• Proof for allowances, such as your child’s birth certificate, social security, life insurance, health insurance and donations
• The amount of tax you paid with your PND 94 (for when you file PND 90)

If you don’t have any of these numbers yet, try setting up a system using Do your online shop’s bookkeeping yourself, without the headache. Next year will be much easier.

The 60% flat deduction or actual expenses: how do you choose?

Quick Answer: Divide your actual expenses for the year by your sales. If it comes to less than 60%, choose the flat deduction. If it is more than 60% and you have full evidence, choose actual expenses.

Here is an example with half-year sales of 400,000 baht:

Shop	Actual expenses	% of sales	Best choice
Homemade baked goods shop	180,000	45%	60% flat deduction (deduct 240,000)
Buy-and-resell shop	300,000	75%	Actual expenses (deduct 300,000)

Actual expenses that count include the cost of goods or ingredients, packaging, shipping, platform fees and advertising, directly related to the shop and backed by evidence.

But if you choose actual expenses, you must keep your receipts and a cash income and expense record available for inspection. If you are audited and have no evidence, those expenses may not be accepted.

The filing steps, click by click (for both PND 94 and 90)

Quick Answer: Go to efiling.rd.go.th, log in, choose the form, fill in your details, tick business income, enter your sales and choose your deduction method, add allowances, check the numbers, then confirm the submission.

Step 1: Go to the website and log in

• Open efiling.rd.go.th and click File a return (ยื่นแบบ) or Log in (เข้าสู่ระบบ)
• The first time, click Register (สมัครใช้บริการ), use your ID number and the Laser ID code on the back of the card, and set a password
• Or choose to log in with ThaID, so you don’t need to remember a password

Step 2: Choose the form

• Choose PND 94 (if filing between July and September) or PND 90 (if filing between January and March)
• Sellers whose income is from selling use PND 90, not PND 91 (91 is for people with salary income only)

Step 3: Your details

• Check your name, address and phone number
• Choose your marital status (single, married, widowed). If married, choose whether your spouse has income, and whether you file jointly or separately

Step 4: Choose your income type

• Tick Income from business, commerce or other, under Section 40(8)
• If you also have a salary or freelance fees, tick those types as well

Step 5: Enter your income and choose a deduction method

• Choose the business type that fits best, such as selling goods
• Enter your total sales for the period you are filing
• Choose the flat deduction or actual expenses (if actual, enter your expense total)
• If tax was withheld, enter the amounts from your 50 Tawi certificates

Step 6: Allowances

• The system adds your personal allowance automatically (PND 94 uses half, which is 30,000 baht)
• Add allowances for children, social security, insurance and others, as they apply to you
• If you logged in with ThaID or a Digital ID, some items will be prefilled from My Tax Account. Check that they are correct before you continue

Step 7: Check and calculate

• The system calculates your tax automatically, including comparing it with the 0.5% of income method in the cases where the law requires it
• For PND 90, don’t forget to enter the tax you paid with your PND 94 so it is deducted

Step 8: Confirm the submission and pay

• Click Confirm submission (ยืนยันการยื่นแบบ). You will get a reference number. Save it or take a screenshot
• If you owe tax, choose to pay by e-Payment, through a bank, by credit card, or print a payment slip to pay at a counter
• If the tax is 3,000 baht or more, the system will ask whether you want to pay in installments, split into 3 payments
• If there is no tax to pay, you’re done. Keep a copy of the submitted return as proof

Common mistakes sellers make

Quick Answer: The most common are entering the amount transferred to your bank account instead of your sales, forgetting to include some channels, and forgetting to deduct the tax you paid with your PND 94.

• Entering the amount the platform paid out instead of your full sales. The payout is the amount after fees. Use your sales figure, and count the fees as an expense instead (if deducting actual expenses)
• Forgetting to include LINE sales or in-person sales. The Revenue Department can see money coming into your account from bank data
• Filing the wrong form, PND 91, even though you have income from selling
• Forgetting to enter your PND 94 tax when filing PND 90, so you pay twice
• Leaving before confirming. A return that hasn’t been confirmed counts as not filed

Once you’ve filed, what next?

Quick Answer: Keep proof of your filing and payment, set a calendar reminder for the next round, and start collecting numbers for next time from today.

• Set reminders for early September for PND 94 and early March for PND 90
• If your total sales for the year are getting close to 1.8 million baht, read When do you need to register for VAT?
• If your profit is getting high enough that the tax is significant, read Register a company, or stay a sole trader for now?
• Watch out for text messages or LINE messages claiming to be from the Revenue Department and asking you to click a link. The Revenue Department does not contact people that way. Always call 1161 to check

The first time may take a while to figure out, but by the second round it only takes a few minutes. Doing it yourself like this is already a big achievement.