The Hidden Risks of Incorrect Tax Invoices — Don’t Let Penalties Surprise You!”

Tax invoices are one of the most important documents in the Thai tax system. They serve as official evidence for both input tax (for buyers) and output tax (for sellers). However, many businesses—especially small enterprises and online sellers—still misunderstand how to properly issue and maintain tax invoices. Let’s explore what the law says, including related penalties and best practices.

1. Legal Basis

According to the Revenue Code, Section 86/4, and related Ministerial Regulations, any person or company registered for VAT (Value Added Tax) must issue a tax invoice every time a taxable sale of goods or services occurs.

A valid tax invoice must contain the following details:

The phrase “Tax Invoice” clearly shown.
The name, address, and taxpayer identification number (TIN) of the seller.
The name, address, and TIN of the buyer (if available).
A description of the goods or services sold.
The quantity, unit price, and total value before tax.
The VAT amount (7% or other applicable rate).
The total amount including VAT.
The date of issuance.
The tax invoice number and the signature (or e-signature) of the authorized person.

2. Types of Tax Invoices

Full Tax Invoice: Used for normal business-to-business (B2B) transactions.
Abbreviated Tax Invoice: Used for retail or small-value transactions (e.g., supermarkets, restaurants).
Electronic Tax Invoice (e-Tax Invoice): Recognized by the Revenue Department if issued and stored through approved e-Tax systems.

3. Retention Period

Both sellers and buyers must keep tax invoices for at least 5 years from the issuance date, or longer if under investigation or pending tax audit.

4. Penalties and Fines

Failing to issue or incorrectly issuing a tax invoice can result in serious legal consequences:

Violation	Relevant Law	Penalty / Fine
Failure to issue a tax invoice	Section 90 of the Revenue Code	Fine up to 2,000 Baht per invoice
Incorrect or incomplete information on tax invoice	Section 90	Fine up to 2,000 Baht
Using false or forged tax invoices	Section 90/4	Imprisonment up to 7 years, or a fine up to 200,000 Baht, or both
Failure to keep tax invoices	Section 87/6	Fine up to 2,000 Baht per missing document

5. Practical Tips for Business Owners

✅ Use an accounting system that automatically generates tax invoices compliant with Revenue Department requirements.✅ Consider switching to e-Tax Invoice & e-Receipt to reduce paperwork and avoid loss or damage.✅ Always verify that your supplier’s tax invoice contains their correct VAT registration number.✅ Conduct regular internal audits to ensure all issued and received invoices are properly recorded.

6. Conclusion

Issuing a proper tax invoice is not just a compliance requirement—it is a critical safeguard for your business against tax disputes. By following the Revenue Department’s rules, you protect your right to claim input VAT and maintain your company’s credibility in the eyes of both clients and the authorities.

If you’re unsure whether your current tax invoices meet legal standards, consult a professional accountant or contact us for a compliance review.