How to Issue a Tax Invoice (ใบกำกับภาษี) in Thailand: Required Contents, Timing, and Penalties

In short

A VAT-registered operator must issue a tax invoice and its copy immediately when the VAT liability arises on every sale of goods or provision of services, and deliver it to the buyerSection 86; the invoice must state at least the 8 categories of items listed in Section 86/4, and copies must be kept for at least 5 yearsSection 87/3. Failing to issue, issuing without authority, or using fake tax invoices can attract a penalty of up to twice the tax shown on the invoice, and even criminal liabilitySection 89Section 90/4.

Who must issue a tax invoice — and who must not?

The tax invoice (ใบกำกับภาษี) is the core document of Thailand's VAT system. Under Section 86, a VAT-registered operator (generally a business required to register because its annual turnover exceeds THB 1.8 million; the standard rate is currently 7%) must prepare a tax invoice and its copy for every sale of goods or provision of services, issue it immediately when the VAT liability arises, and deliver it to the purchaser or service recipient. As a rule, tax invoices are issued separately for each place of business, unless the Director-General of the Revenue Department determines otherwise; an operator granted temporary registration may issue tax invoices only under the conditions determined by the Director-General.

Conversely, the law also spells out who is prohibited from issuing tax invoices: a registered operator located outside Thailand whose representative already issues tax invoices on its behalf, an operator providing electronic services from abroad to non-registered users in Thailand, and a registered operator whose assets have been seized and sold at auction, among others, are all barred from issuing tax invoices themselvesSection 86/1. A registered operator located outside Thailand that wishes to have its representative issue tax invoices in its name must first apply to the Director-General for approval; the approved representative must issue invoices under the conditions determined by the Director-General, and bears the same and joint liability with that operator in matters concerning the tax invoicesSection 86/2.

Most important of all: no person other than a registered operator or a person authorized by law may issue a tax invoice, debit note, or credit note; anyone who issues one without authority is liable for VAT in the amount shown on the document, as though they were a registered operatorSection 86/13.

When to issue? Follow the point where VAT liability arises

Section 86 requires the invoice to be prepared "immediately when the liability to pay VAT arises", so the timing of issuance depends on when the VAT liability arises:

Sale of goods: as a rule, full liability arises upon delivery of the goods; but if any of transfer of ownership, receipt of payment, or issuance of a tax invoice occurs before delivery, liability arises earlier, in proportion, at the time of that actSection 78. For installment sales where ownership has not passed on delivery, liability arises on each installment due date.
Provision of services: as a rule, liability arises when payment for the service is received; if a tax invoice is issued or the service is used before payment is received, liability arises earlier, in proportion, at the time of that actSection 78/1.

In practice this means: for goods, you cannot wait for payment before invoicing — once the goods are delivered, the obligation to issue has arrived; and deposits or advance payments received earlier also trigger the invoicing obligation early, in proportion. The timing rules for goods and services differ, and businesses that sell both are especially prone to mixing them up.

What must a tax invoice state? (Section 86/4, item by item)

Apart from the special cases under Section 86/5 and Section 86/6, a compliant tax invoice must state at least the following itemsSection 86/4:

(1) The words "tax invoice", in a conspicuous place;
(2) Issuer details: the name, address, and tax identification number of the registered operator issuing the invoice; where a representative or an auctioneer issues the invoice in the name of the registered operator, the name, address, and tax identification number of that representative must also be stated;
(3) Buyer details: the name and address of the purchaser of goods or recipient of services;
(4) The serial number of the invoice, and the volume number if issued in volumes;
(5) The name, type, category, quantity, and value of the goods or services;
(6) The amount of VAT, calculated on the value of the goods or services and shown clearly separated from that value;
(7) The day, month, and year of issuance;
(8) Any other items prescribed by the Director-General.

The same section also requires the invoice to be prepared in Thai language, in Thai currency, and in Thai or Arabic numerals; specific types of business that genuinely need to use a foreign language or foreign currency may do so only with the Director-General's approvalSection 86/4. Several goods or services may in principle be combined on a single invoice, unless the Director-General requires a particular category of goods or services to be invoiced separately. For certain oil products, tobacco, invoices approved to be issued in foreign currency, and similar cases, the Director-General may prescribe different itemsSection 86/5.

When can a simplified tax invoice be used?

For retail or minor-service businesses serving large numbers of walk-in customers, the law provides two facilitation channels:

Simplified tax invoice Retail business

A business determined by the Director-General to be retail in nature has the right to issue a simplified tax invoice (ใบกำกับภาษีอย่างย่อ), but a representative may not issue one. A simplified invoice must state: the words "tax invoice", the issuer's name (or abbreviated name) and tax identification number, the serial number, the name, type, quantity, and value of the goods or services, a price expressly shown as VAT-inclusive, the date of issuance, and any other items prescribed by the Director-General. Product names may be shown as codes, provided they are notified to the Director-General at least 15 days in advance; using a cash register to issue simplified invoices requires the Director-General's prior approval. Prices displayed in retail business must be VAT-inclusiveSection 86/6.

Small-transaction exemption Minor single sales

For minor sales or minor service businesses as determined by the Director-General, no tax invoice needs to be issued for a single transaction not exceeding the amount determined by the Director-General (statutory cap THB 1,000) — but one must still be issued if the buyer requests itSection 86/8.

Ordinary tax invoice Default rule

Ordinary B2B transactions not covered by the above determinations still require a full tax invoice stating all the items in Section 86/4 — and buyers will usually insist on one, because their input tax deduction depends on itSection 82/5.

Input/output tax reports and record-keeping duties

Issuing the invoice is only step one — the accompanying reporting and archiving duties are just as much an audit focus:

Three reports: a registered operator must prepare an output tax (sales tax) report and an input tax (purchase tax) report, and operators selling goods must also prepare a goods and raw materials report; the reports follow the form prescribed by the Director-General, are prepared separately for each place of business, and entries must be made within 3 working days of receiving or disposing of the goods or servicesSection 87.
Retention period: reports, tax invoices, invoice copies, and related supporting documents must be kept at the place of business where the report was prepared (or another place prescribed by the Director-General) for not less than 5 years (counted from the date of filing the return or preparing the report); if the business ceases, they must be kept for a further 2 years from cessation; the Director-General may, where deemed appropriate, require a longer period, but not more than 7 years. Invoices used for the input tax report must be arranged in order, matching the report entries one to oneSection 87/3.
The buyer's perspective: where there is no tax invoice, the invoice is incorrect or incomplete in a material part (as determined under criteria prescribed by the Director-General), or the invoice was issued by a person without authority to issue it, the corresponding input tax cannot be deductedSection 82/5. Checking every Section 86/4 item on the invoices you receive is the first line of defense for your own deduction right.

Consequences of violations: doubled penalties, and prison for serious cases

The administrative penalties directly related to tax invoices (which, under the final paragraph of Section 89, may be waived or reduced under Director-General regulations approved by the Minister) includeSection 89:

Not issuing or not delivering: failing to prepare a tax invoice and deliver it to the buyer as required — a penalty of twice the tax shown on the invoice;
Issuing without authority: issuing a tax invoice, debit note, or credit note without authority — a penalty of twice the tax shown on the invoice;
Using fake invoices: calculating tax using a fake tax invoice (in whole or in part) — a penalty of twice the tax shown on the invoice; where the beneficiary cannot prove who issued the invoice, it is deemed fake;
Not keeping copies: failing to keep copies of output tax invoices as required — a penalty of 2% of the tax shown on the invoices; failing to keep input tax invoices used for deduction — a penalty of 2% of the tax deducted.

On the criminal side: failing to prepare or deliver a tax invoice is punishable by imprisonment of up to 1 month or a fine of up to THB 5,000, or bothSection 90/2; issuing without authority, deliberately not issuing in order to evade tax, or deliberately using forged or unlawfully issued tax invoices for deduction is punishable by imprisonment of 3 months to 7 years plus a fine of THB 2,000 to 200,000Section 90/4.

⚠️ Never issue tax invoices for others or buy and sell them

Issuing invoices "on behalf of" someone else, or buying invoices to claim deductions, is not a grey area in Thailand: the unauthorized issuer must pay VAT in the amount shown on the invoiceSection 86/13, plus a penalty of twice the taxSection 89, and may face 3 months to 7 years of imprisonmentSection 90/4. Even a user who claims not to have known will be penalized for using a fake invoice if they cannot explain where the invoice came from.

The three most common mistakes in practice

Wrong timing Most frequent

Treating "payment received" as the invoicing trigger. For sales of goods, VAT liability in principle arises on deliverySection 78, and the invoice must be issued immediately at that pointSection 86 — catching up at month-end, or invoicing only upon payment, may both constitute failure to issue on time.

Missing items Drags the buyer down

Omitting the buyer's address or tax ID, or not showing the VAT amount separately from the price, falls short of the minimum requirements of Section 86/4Section 86/4; for the buyer, an invoice that is incorrect or incomplete in a material part can directly disqualify the input tax deductionSection 82/5, which easily sparks commercial disputes.

Archiving lapses Sitting-duck penalties

Report entries not made within 3 working daysSection 87, copies not kept for the full 5 years, input invoices not filed in report orderSection 87/3 — nothing shows in day-to-day operations, but come a tax audit each one is a ready-made penalty itemSection 89.

How SLF can help

SLF Accounting provides one-stop monthly bookkeeping and VAT filing services for Thai and foreign businesses operating in Thailand: we check whether your invoice template satisfies every mandatory item under Section 86/4, confirm the correct issuance timing for your type of business, prepare the output and input tax reports and file on schedule, and set up a document archiving system that meets the requirements of Section 87/3. For e-tax invoices and other specific formats and details prescribed by the Director-General, the official regulations prevail, and our firm can help you confirm them. If you have just completed VAT registration in Thailand, or have received an inquiry from the Revenue Department about invoice issues, feel free to contact us for a compliance health check.

FAQ

Our company just completed VAT registration — do we have to issue a tax invoice for every single sale?

Yes. Section 86 requires a registered operator to prepare a tax invoice and its copy for every sale of goods or provision of services, and to deliver it to the buyer immediately when the VAT liability arises. Only minor businesses as determined by the Director-General are exempt, for a single transaction not exceeding the amount determined by the Director-General (statutory cap THB 1,000) — and even then, an invoice must still be issued if the buyer requests one (Section 86/8).

The goods have been delivered but we have not been paid yet — do we need to issue the tax invoice already?

Generally yes. For sales of goods, the VAT liability in principle arises upon delivery of the goods (Section 78), and the tax invoice must be issued immediately when the liability arises (Section 86); if payment is received, ownership is transferred, or an invoice is issued before delivery, the liability arises earlier, in proportion. For services, the principal tax point is receipt of the service fee (Section 78/1).

We received a tax invoice with incomplete details — can we still deduct the input tax?

It is risky. Section 82/5 provides that input tax cannot be deducted where there is no tax invoice, where the invoice is incorrect or incomplete in a material part (as determined under criteria prescribed by the Director-General), or where the invoice was issued by a person without authority to issue it. When receiving an invoice, check each mandatory item under Section 86/4 one by one — both parties' names and addresses, the issuer's tax ID, and whether the VAT amount is shown separately from the price.

How long must tax invoices and copies be kept, and what happens if they are not kept?

Reports, invoices, and copies must be kept for not less than 5 years from the date of filing the return or preparing the report, plus a further 2 years after ceasing business; the Director-General may require a longer period, but not more than 7 years (Section 87/3). Failing to keep copies of output tax invoices as required attracts a penalty of 2% of the tax shown on the invoices; failing to keep input tax invoices used for deduction attracts a penalty of 2% of the tax deducted (Section 89).