What is an e-Tax Invoice?

An e-Tax Invoice is a tax invoice prepared as an electronic file rather than paper, certified by the Revenue Department through a Digital Signature or a Time Stamp that confirms the document was not altered after issue. Unlike a paper tax invoice that gets printed and filed, an e-Tax Invoice reaches the buyer and the Revenue Department at the same time, cutting down on paper storage and making records faster to retrieve if the Revenue Department asks to review them. The Revenue Department offers two main formats. e-Tax Invoice by Time Stamp suits small VAT-registered businesses with revenue up to 30 million baht a year: you prepare a PDF/A-3 file and email it to the customer while copying the Revenue Department's stamping address, with no need to buy digital signature software. e-Tax Invoice & e-Receipt has no revenue cap but requires a digital certificate or software that connects directly to the Revenue Department's system — better suited to businesses issuing a high volume of tax invoices daily, such as large retail chains or e-commerce platforms. Registration happens at rd.go.th/27659.html by submitting form Kor.Or.01, receiving an activation code, setting a password, and getting a user code starting with CM followed by the 13-digit tax ID. For a small online shop that just registered for VAT and issues a few dozen tax invoices a month, e-Tax Invoice by Time Stamp is usually the more practical option since it needs no extra system investment. A shop selling across several channels and issuing hundreds of tax invoices a day should consider e-Tax Invoice & e-Receipt, which connects directly to accounting software. Revenue thresholds and registration steps can change, so check the latest notice at rd.go.th before applying.