What Is e-Invoicing in Thailand? #
Thailand’s Revenue Department has established a voluntary electronic tax invoice system designed specifically for SMEs with annual revenue not exceeding THB 30 million. This system, called e-Tax Invoice by Email, allows businesses to issue electronic tax invoices through email instead of paper .
The key mechanism is a Time Stamp issued by ETDA (Electronic Transactions Development Agency), which replaces the digital signature required in the full e-Tax Invoice system . This makes it simpler and more accessible for smaller businesses.
Important requirements include :
- PDF/A-3 format only (with embedded XML, mandatory since July 2018)
- One invoice per file, maximum 3 MB
- Email must be sent to the buyer and CC’d to
csemail@etax.teda.th - Subject line must follow the format:
[Date][INV][Invoice Number]
The system remains voluntary – paper invoices can still be used in parallel .
Thailand’s Revenue Department operates two parallel e-Tax Invoice systems, each designed for different taxpayer segments:
| e-Tax Invoice & e-Receipt | e-Tax Invoice by Email | |
|---|---|---|
| Target | All businesses (no revenue limit) | SMEs with annual revenue ≤ THB 30 million |
| File Format | PDF, PDF/A-3, XML | PDF/A-3 only (with embedded XML) |
| Authentication | Digital Signature + CA | ETDA Time Stamp (no digital signature) |
| Submission | Upload, Host-to-Host, Service Provider | Email (with CC to ETDA system) |
| Current Status | Voluntary | Voluntary |
How AccountingSuite Works for Thai e-Invoicing #
AccountingSuite already provides the core capability needed for the email-based approach to Thai e-Tax Invoice:
1. Email Delivery of Sales Invoices #
From any Sales Invoice in AccountingSuite, you can click the Email button to send the invoice directly to your customer . The email address auto-fills from the customer record if entered. You can add CC recipients and custom notes to the email.
For configuration, AccountingSuite supports SMTP/IMAP email settings, allowing you to connect your business email account and send invoices from your registered address .
2. Customizable Print Form Templates #
AccountingSuite allows you to edit print form templates to match the required format for Thai e-Tax Invoices . You can:
- Add or remove fields (tax ID, invoice number, dates, etc.)
- Adjust layout and column widths
- Add your company logo and branding
- Include amount in words if needed
This means you can create a dedicated print form that replicates the Thailand’s Revenue Department-compliant invoice layout, then send it as a PDF attachment via email.
Important: The current AccountingSuite email function sends standard PDF attachments. For full compliance with Thai e-Tax Invoice by Email, the PDF must be in PDF/A-3 format with embedded XML, and the email must be CC’d to
csemail@etax.teda.thwith the correct subject line format.
The Path to Full e-Invoicing Compliance #
AccountingSuite’s email delivery + custom print form approach provides a foundation for Thai e-Tax Invoice compliance. To achieve full compliance, it would need:
| Requirement | Current AccountingSuite | What’s Needed |
|---|---|---|
| Custom invoice layout | ✅ Editable print forms | Configure Thai-compliant template |
| Email sending | ✅ Built-in email | Send from registered email |
| PDF/A-3 output | ⚠️ Standard PDF | PDF/A-3 with embedded XML |
| CC to ETDA system | ✅ CC field available | Add csemail@etax.teda.th |
| Subject line format | ✅ Editable subject | Use [Date][INV][Number] format |
| Time-stamped receipt storage | ❌ | Archive ETDA return email |
Need Direct Integration? #
If you require direct XML exchange with the Thai Revenue Department (rather than the email-based SME approach), or need automated PDF/A-3 generation with embedded XML, we can build a custom solution.
To proceed, we need:
- A test account / test environment access from the Thai Revenue Department or ETDA
- Sample XML schema output expectations
- Confirmation of your registration status with the Revenue Department
Contact us if you are ready to discuss a Thailand-specific e-invoicing integration.
Official References #
- Thai Revenue Department e-Tax Invoice Portal: https://etax.rd.go.th
- e-Tax Invoice by Email System (ETDA): https://www.etax.teda.th
- Revenue Department main site: https://www.rd.go.th
Disclaimer: This article is for informational purposes only. The e-Tax Invoice system in Thailand is voluntary and subject to Revenue Department regulations. Consult a qualified tax professional regarding your specific situation.