What tax invoices does an online store issue?
If your business is registered for VAT, every sale needs a tax invoice. For shoppers buying for themselves, a retailer can usually issue an abbreviated tax invoice, the short form you get at a till. When the buyer is a business that wants to claim input VAT, they need a full tax invoice.
That full invoice carries their company name, address, 13-digit tax ID and branch. Online stores in Thailand get both kinds of buyer, so the website has to handle both.
e-Tax simply means issuing those documents electronically under rules set by the Revenue Department, instead of printing and posting paper. It is optional for most sellers, but it saves paper, postage and a lot of retyping once orders grow. This page explains the options in website terms. It is not tax advice: the rules below are summarised from the Revenue Department's published material at the time of writing, and your accountant should confirm how they apply to your business.
If you are not VAT-registered yet, most of this does not apply today, but it is worth designing checkout so it can be switched on later. The registration steps for an online shop itself are covered in our note on DBD registration and the trustmark for Thai online stores.
The two e-Tax routes
The Revenue Department runs two electronic routes. They differ in who can use them and in how much technical work sits behind each invoice.
e-Tax Invoice & e-Receipt is the full scheme. You apply to the Revenue Department, sign each document with a digital certificate, produce it in the XML format based on the ETDA standard, and submit the data to the Revenue Department. Larger sellers often do this through an approved service provider that handles signing and submission for them.
e-Tax Invoice by Email is the lighter route intended for smaller businesses. The invoice is sent by email through a time-stamping service recognised by the Revenue Department, which records it. Eligibility is limited by annual revenue; at the time of writing the published limit was THB 30 million, but check the current rule on the Revenue Department's e-Tax site before relying on it.
| e-Tax Invoice & e-Receipt | e-Tax Invoice by Email | |
|---|---|---|
| Who it suits | Any VAT-registered seller approved by the Revenue Department, including high-volume stores | Smaller sellers within the revenue limit set by the Revenue Department |
| Signing | Digital certificate on each document | Time stamp applied by the email service |
| Format | XML to the ETDA standard, often with a PDF copy for the buyer | PDF or similar attached to an email |
| Submission | Data sent to the Revenue Department, directly or via a service provider | Recorded through the email time-stamping service |
| Website work | Integration with a provider's API or your accounting system | Store or accounting tool sends the invoice email in the required way |
Who must, and who may
Two separate questions often get mixed up.
Who must issue tax invoices
Every VAT-registered business must issue a tax invoice for taxable sales. VAT registration becomes compulsory once annual turnover passes the threshold in the Revenue Code, which at the time of writing is THB 1.8 million; some businesses register voluntarily below it. A shop under the threshold and not registered does not issue tax invoices at all, only ordinary receipts.
Who may choose e-Tax
Issuing those invoices electronically is a choice. You can stay on paper, use e-Tax by Email if you qualify, or apply for the full scheme. What you cannot do is send an ordinary PDF by email and treat it as a valid electronic tax invoice: it needs to go through one of the recognised routes.
The practical question for a store owner is volume. Ten business orders a month can be handled by an accountant issuing invoices from the accounting software. Hundreds a month justify connecting the store so the invoice is created from the order automatically. That is also the point where the rest of your stack matters: how payment gateways compare in Thailand affects what payment reference lands on the invoice, and your courier and shipping integration decides when an order counts as fulfilled.
Asking for tax details at checkout
Most buyers do not want a full tax invoice, so the fields should stay out of their way. The pattern we use is a single checkbox, "I need a full tax invoice", which opens a small group of fields:
- Company or individual name as registered
- 13-digit tax identification number, checked for length and digits only
- Head office or branch number
- Registered address, which may differ from the delivery address
Keep the billing address separate from shipping. A Bangkok company may order to a warehouse in Samut Prakan while the invoice must show the registered office. Label the fields in Thai and English, because accounts staff often place the order in Thai while the manager reads the site in English.
Also decide what happens after payment. If the buyer forgets to tick the box, can they request a full invoice from their account page within your accountant's cut-off? A short line on the checkout page explaining your policy prevents awkward emails at month end. Clear wording here belongs with the rest of your buying information, in the same spirit as good product page practice: answer the question before the customer has to ask it.
Connecting WooCommerce
WooCommerce does not issue Thai e-Tax documents on its own. There are three workable routes:
- Through your accounting software. Many Thai cloud accounting tools can issue e-Tax documents and accept orders through an API, as our guide to connecting accounting software to a Thai store explains. The store sends each paid order with the tax fields; the accounting tool creates, signs or time-stamps and sends the invoice. This keeps tax logic with the system your accountant already uses.
- Through an e-Tax service provider. A provider approved for the full scheme receives order data from WooCommerce, issues the signed document and handles submission. This suits higher volume and stores that do not want accounting software involved in every order.
- Through a plugin. Some plugins generate Thai tax invoice PDFs. Check carefully whether a plugin only produces a nicely formatted PDF or actually uses a recognised e-Tax route. Only the second counts as an electronic tax invoice.
Whichever route you pick, test with real edge cases before launch: a refund after invoicing, a partial shipment, an order paid by PromptPay and one by COD. Credit notes need the same care as invoices.
Connecting Shopify
On Shopify the options are apps and providers. Look in the Shopify App Store for apps that mention Thai tax invoices or e-Tax, and confirm which Revenue Department route they use, or connect Shopify to Thai accounting software that supports e-Tax through its own integration. Shopify's checkout limits how freely you can add fields, so the "full tax invoice" details are often collected through the app's own form or checkout extension rather than custom code. Ask the app vendor for a sample invoice and check it with your accountant before you rely on it.
Records, retention and PDPA
Tax invoices and supporting records have to be kept for the period the Revenue Code requires, generally at least five years and longer in some situations; your accountant will tell you the period that applies. For e-Tax documents that means keeping the signed files or the time-stamped emails, not just the store's order list, and making sure they survive a change of platform or accounting tool.
Tax IDs, names and registered addresses are personal data under the PDPA when the buyer is an individual, and still sensitive business information when it is a company. Alongside a PDPA-compliant checkout and privacy notice, a few habits help:
- Limit who in the store admin can see and export billing details.
- Mention in your privacy notice that tax details are collected to issue invoices and shared with your accounting provider.
- Do not copy invoice data into chat groups or shared spreadsheets to "fix" it later.
Selling abroad adds another layer, since overseas buyers rarely have a Thai tax ID and VAT treatment for exports differs; our guide to cross-border e-commerce from Thailand picks that up.
Where our e-commerce setup fits
e-Tax invoice setup is part of our E-commerce package, alongside Shopify or WooCommerce, PromptPay, cards, COD, Thai couriers, product import, staff training and a launch checklist. In practice that means we build the checkout fields, connect the store to the route you and your accountant have chosen, and test it with real orders before launch. The tax decisions themselves stay with you and your accountant.
If you are still mapping out the whole store, start with our step-by-step on how to create an e-commerce website in Thailand. When you are ready to talk about a build, see our service for building an online shop and the online store pricing, which starts from THB 50,000 as an indicative one-time figure. The final price is set in a written quote. A typical project takes around 15 days; large catalogues can take longer. Message us on WhatsApp at +66 93 004 4098 or email service@websitedevelopmentbangkok.com with your platform and accounting software.
More e-commerce guides
Sources
- Revenue Department: e-Tax Invoice & e-Receipt
- Revenue Department (Revenue Code, VAT and tax invoices)
- Electronic Transactions Development Agency (ETDA)
- Personal Data Protection Act B.E. 2562 (2019), English translation
- Revenue Department: VAT registration threshold and rate
- e-Tax Invoice by Email time-stamping service
Builds and ranks the websites: the systems behind the 17 client sites whose Search Console numbers we publish. This guide was written by the Website Development Bangkok team. More about us