VAT Filing in Thailand: What Your Business Needs to Do Every Month
(Updated May 2026) This guide covers the essentials: when VAT registration is required, how VAT filing Thailand works in practice, and the common mistakes that cost businesses money.
When Is VAT Registration Required in Thailand?
Any business in Thailand with annual revenue exceeding 1.8 million THB is legally required to register for VAT within 30 days of exceeding the threshold. This applies to most goods and services, with specific exemptions for certain categories including unprocessed agricultural products, educational services, and healthcare.
You can also register voluntarily before reaching the threshold. Some businesses do this to claim input tax credits from the start. Registration is handled through the Revenue Department, and you will need your company's Tax ID to apply. For full details on the registration process itself, see our VAT Registration service page.
The standard VAT rate in Thailand is 7% (reduced from the statutory 10% under Royal Decree No. 799, currently in effect through 30 September 2026).
Monthly VAT Filing Obligations in Thailand
Once registered, three things apply immediately and continuously:
1. Monthly PP.30 Returns
Every month, without exception, you must file a PP.30 VAT return by the 15th of the following month (or the 23rd if filing electronically). This applies even if your company had zero revenue that month. A nil return is still a required return. Late filing carries a fine of 300 THB if filed within seven days, rising to 500 THB after that (and up to 2,000 THB for failure to file), plus a 1.5% monthly surcharge on any unpaid VAT. In serious cases, the Revenue Department can impose an additional penalty of up to 200% of the tax due.
2. VAT Invoices
You must issue tax invoices for every taxable sale. These must meet the Revenue Department's format requirements under Section 86/4 of the Revenue Code, including the words "Tax Invoice" displayed prominently, your VAT registration number, the buyer's name, address, and taxpayer identification number, a description and quantity of goods or services, the VAT amount shown separately, and the date of issue. Invoices that do not comply can result in your customers being unable to claim input tax credits, which creates problems for both parties.
3. Record Keeping
All purchase and sales tax invoices must be retained for at least five years from the date of filing. The Director-General may extend this to seven years, and for electronic invoices the seven-year period applies by default. The Revenue Department can audit any period within this window, and incomplete records lead to disallowed input tax credits and potential penalties.
Input VAT vs Output VAT: How It Works
This is the part that matters most for your bottom line. VAT is not simply a tax you pay. It is a system of credits:
Output VAT is the 7% you charge your customers on sales. You collect this and owe it to the Revenue Department.
Input VAT is the 7% you pay on business purchases such as office rent, equipment, professional services, and supplies. You can credit this against your output VAT.
Your monthly PP.30 return calculates the difference. If output exceeds input, you pay the balance. If input exceeds output, which is common in early-stage businesses with high setup costs, you can carry the credit forward or apply for a refund.
The key requirement: you can only claim input VAT if you hold a valid tax invoice from the supplier. No invoice, no credit. This is why proper documentation from every supplier matters from day one.
Common VAT Mistakes Foreign Businesses Make in Thailand
Not Filing Nil Returns
The single most common mistake. If your company is VAT-registered and had no sales this month, you still file PP.30. Penalties are automatic and they stack month on month.
Claiming Input VAT Without Proper Invoices
If the tax invoice does not meet the Revenue Department's requirements (wrong format, missing registration number, incomplete details) the credit will be disallowed during an audit.
Registering Too Late
If your revenue crossed the 1.8 million THB threshold and you did not register, the Revenue Department can assess VAT retrospectively from the date you should have registered, plus penalties and surcharges on the unpaid amount.
Confusing VAT with Withholding Tax
These are separate systems. Withholding tax is deducted from payments you make to suppliers. VAT is charged on sales. Both have monthly filing deadlines on the 15th, but they are different returns filed under different form numbers. Our 2026 Thailand Tax Calendar lays out every deadline side by side.
Managing monthly VAT filing alongside withholding tax and payroll is exactly why most foreign-owned companies work with an accounting firm. Our bookkeeping and accounting packages include monthly VAT filing as standard. Get in touch if you need support.
Frequently Asked Questions: VAT Filing Thailand
Does my company need to register for VAT if revenue is below 1.8 million THB?
No, registration is not mandatory below the threshold. However, you can register voluntarily if you want to claim input tax credits on business purchases from the outset. This can make sense for businesses with high early-stage costs.
How long does VAT registration take?
Typically two to four weeks from submission, though processing times at the Revenue Department can vary. Your company must already have a Tax ID before applying.
Can I claim input VAT on purchases made before I registered?
Generally no. Input VAT can only be claimed on purchases made after your VAT registration date. This is one reason some businesses choose to register voluntarily early rather than waiting to hit the threshold.
What is the difference between PP.30 and PP.36?
PP.30 is the standard monthly VAT return for VAT-registered businesses. PP.36 is the reverse-charge form used when a Thai business (whether VAT-registered or not) pays for services from a foreign provider where those services are used in Thailand. The Thai business must self-assess and remit the 7% VAT on the foreign supplier's behalf. VAT-registered businesses can then claim this as input tax on their PP.30 return; non-registered businesses cannot. Note that PP.36 is due by the 7th of the following month (or the 15th for e-filing), which is earlier than the PP.30 deadline.
Do I charge VAT to foreign clients outside Thailand?
Services performed in Thailand but used entirely in a foreign country are zero-rated under Section 80/1(2) of the Revenue Code, meaning you file the return but charge 0% VAT. The legal test is where the result of the service is used, not simply where the client is located. If a service is partially used in Thailand, only the portion used overseas qualifies for zero-rating. You will need documentation proving payment from outside Thailand to sustain a zero-rate claim during an audit. This is worth confirming with your accountant for your particular business.