Country deep dive
A timeline of permissions rather than deadlines. Thailand authorised electronic tax documents in 2022, added a lighter route for smaller businesses in 2023, and paid people to adopt both until the end of 2025.
Issued 8 July 2022 under Revenue Code s.3 odd and s.4 as amended by the Revenue Code Amendment Act (No. 53), published in the Royal Gazette on 20 July and in force thirty days later. It permits electronic preparation, delivery and retention of tax documents. Read what it does carefully: it authorises, it does not compel, and every Thai e-invoicing instrument since has kept that shape.
Announced by the Revenue Department on 12 May 2023 and effective from this date. A VAT registrant with annual revenue up to THB 30 million may e-mail a PDF/A-3 invoice to the buyer, copying ETDA, which applies a trusted time stamp and returns the stamped file to both parties. The Thai instruments call this the Time Stamp route; the Revenue Department's user-facing pages call it e-Tax Invoice by Email. They are the same thing.
Royal Decree No. 766 gave a double deduction — the ordinary 100 per cent plus a further 100 — for investment in e-Tax Invoice, e-Receipt and e-Withholding Tax systems, covering hardware, software and service-provider fees. The implementing Director-General announcement is dated 28 June 2023 and applied retroactively from 1 January 2023. Thailand drives adoption with incentives rather than obligations, and this is the clearest instance.
Royal Decree No. 766 ran to 31 December 2025 and was not renewed before it lapsed. On 16 June 2026 the Cabinet approved a two-year extension at the same 200 per cent for 2026 and 2027, newly covering ETDA system-assessment fees, together with a cut in e-Withholding Tax rates to a flat 1 per cent. The Revenue Department announced it in press release 14/2569. As at 27 August 2026 no enacting Royal Decree appears on the Department's own decree index, so expenditure incurred during 2026 rests on an approved but unpromulgated measure.
Press release 20/2569 reports an operation against fraudulent tax invoices with damage put at around 360 million baht, following a similar action earlier in the year. It is recorded here because it answers the question a reader actually has about a country with no mandate: where does the tax administration put its effort? In Thailand the answer is anti-fraud enforcement and incentives, not obligation.
The full system uses XML on the UN/CEFACT Cross Industry Invoice model, not UBL and not EN 16931. The e-mail route uses PDF/A-3. Thailand has no Peppol Authority.
Everyone may, nobody must. What has scope is the choice between the two routes: the e-mail route is capped at THB 30 million of annual revenue, and a business cannot run both at once.
The useful work here is deciding whether to opt in at all, and then not over-building. Nothing on this page requires a compliance project, and the incentive that used to pay for one has lapsed.
Both routes are voluntary in the words of their own instruments — clause 12 of Announcement No. 15 lets you choose electronic or paper per transaction. Write that down with the citation, because a vendor page may tell your team otherwise.
Below it, the e-mail route needs no certificate, no XML and no monthly send. Above it, only the full system is open. You cannot be on both, so decide before you build anything.
An enterprise certificate under the National Root CA on a token or an HSM at FIPS 140-2 Level 3 or above, plus XAdES signing and a monthly XML send by the fifteenth. That is the real cost of this route.
The 2025 and 2028 milestones circulating in commentary appear in no Revenue Department source. Building a mandate-shaped project against unsourced dates is how budgets get spent on obligations that never arrive.
The Cabinet approved it in June 2026 and no Royal Decree has appeared. Keep the invoices and the ETDA assessment fees documented, and check the Department's decree index before you rely on the relief.
Revenue Code s.87/3 sets five years from filing, extendable by the Director-General to no more than seven. Electronic retention is expressly permitted, provided meaning, reproducibility and metadata survive.
There is no e-invoicing penalty, because there is no e-invoicing rule. What the Revenue Department enforces hard is invoice authenticity, through fraud investigations rather than format checks.
Other countries in the same region, ordered by their next dated milestone. Each links to a full briefing.