Key Takeaways
- This chapter is for a narrow audience: software, SaaS and e-commerce sellers who bill Thai customers without opening a Thai company. If you already have, or plan to have, a Thai entity, the rest of this guide covers you and you can skip ahead.
- Thailand’s e-Service VAT regime has applied to foreign digital service providers since 2021. The threshold is THB 1.8 million a year from Thai customers who are not themselves VAT-registered, and the rate simply follows whatever the standard VAT rate is.
- The real risk is not VAT. It is permanent establishment, and the single biggest trap is a pure day count: more than 183 days of on-the-ground service delivery in any 12-month period creates one, with no office required.
- A 2025 Revenue Department ruling reclassified genuine SaaS access fees as business profits rather than royalties, which is good news. But it interprets Thailand’s treaties with the US, Ireland and Hungary, not Singapore. A Singapore seller has to check its own treaty article, not borrow this one.
In Detail
Who should read this chapter
Most of this guide assumes you are deciding whether to set up a Thai company. This chapter assumes the opposite: you are already selling to Thai customers, or about to, and you want to know what you owe and what you risk without one. That is a real question, but it is a specific one. If your business involves people on the ground in Thailand, a Thai distributor, or physical goods crossing the border, most of this chapter does not apply to you in the same way. It is written for a Singapore-based software, SaaS, subscription or e-commerce business billing Thai customers remotely.
The e-Service VAT regime
Since 2021, a foreign provider of electronic services, or a platform facilitating them, has had to register for and charge Thai VAT once its revenue from Thai customers who are not themselves VAT-registered exceeds THB 1.8 million a year. The threshold has not moved since.12 The rate simply tracks whatever the standard VAT rate happens to be. That rate is nominally 10 percent, but Thailand has run a reduced 7 percent rate continuously since 1992 and has just extended it again, this time through 30 September 2027.3
If your customer is a Thai VAT-registered business rather than a consumer, you are largely out of this. The transaction is handled through the reverse-charge mechanism, Form PP.36: the Thai business self-assesses the VAT, and you as the foreign vendor do not need to register at all for that sale. You do still need to confirm your counterpart is actually VAT-registered before relying on this.12
The myth to retire: VAT registration does not create a permanent establishment
A lot of foreign sellers avoid registering for e-Service VAT, or delay it well past the threshold, because they believe registering will flag them to the Revenue Department as having a taxable presence in Thailand. That reasoning is backwards. VAT registration is a consumption-tax mechanic tied to where your customers are. Permanent establishment is a corporate income tax question tied to where your business actually operates. Registering for VAT does not, by itself, create one. Conflating the two leads people to under-register for VAT while doing nothing about the PE risk that might genuinely apply to them, which is the wrong trade in both directions.
Permanent establishment, from the treaty itself
The Singapore-Thailand double tax agreement sets out what actually creates a taxable presence, and it is worth reading directly rather than through a summary, because most summaries only cover the first of its three tests.
The first is the one people already picture: a fixed place of business. An office, branch, factory, workshop, or place of management in Thailand through which your business is wholly or partly carried on creates a PE. Purely preparatory or auxiliary activity, such as storage, display, or gathering information, is carved out and does not.4
The second is the one a services exporter is actually exposed to: a service PE. This is deemed to exist where your company furnishes services in Thailand through personnel, for the same or a connected project, for periods that add up to more than 183 days within any 12-month period. There is no office requirement at all. It is a pure day count, and the days are aggregated across the rolling 12-month window, not reset by a calendar year or by gaps between trips.4
The third is a dependent agent PE: someone acting for you in Thailand who has, and habitually exercises, authority to conclude contracts in your name, or who habitually plays the principal role leading to contracts that are routinely concluded without material change on your side. A genuinely independent agent, such as a broker or general commission agent acting in the ordinary course of its own business, does not create this.4
How the 183-day trap actually accumulates
Say your Singapore company sends a two-person implementation team to a Bangkok client for a six-week onboarding project in February and March: about 84 person-project-days if you count each person separately against the project, but the day count for this test runs by calendar days the service is being furnished, not head count, so treat it as roughly 42 days of the project being actively worked in Thailand. The same client brings you back in June and July for a further 60 days of configuration work on the same system. A different consultant returns in November for another 90 days supporting the same rollout. None of these trips looks large on its own. Added together for the same or a connected project, that is around 192 days inside a 12-month window, and the service PE threshold is crossed.4 The mistake is treating each engagement as a separate, short trip. The treaty does not see it that way if the projects are connected.
What a PE actually costs you
Once a PE exists, the profits attributable to it become subject to Thai corporate income tax at the standard 20 percent rate, the same rate that applies to an ordinary Thai company.5 Without a PE and without registering as a company, the domestic withholding tax rate that applies to Thailand-source payments to a foreign company is 15 percent, well above the treaty-reduced rates on dividends, interest and most royalties.6 Claiming the lower treaty rate is not automatic either: it needs a Certificate of Residence from IRAS and a Thai Double Tax Relief request lodged at or before payment, and without that paperwork in hand the Thai payer withholds at the higher domestic rate first, leaving you to chase a slower refund afterward.
The SaaS ruling, and the half of it that gets left out
In March 2025 the Thai Revenue Department issued Tax Ruling Gor.Kor. 0702/1626, revisiting how payments for cloud and SaaS access should be classified. The favourable reading, and the one that gets repeated most often, is real: a genuine subscription that only grants a limited, revocable right to use the software, with no reproduction, adaptation or distribution rights, is treated as business profits rather than a royalty. Combined with no Thai PE, that puts a typical SaaS subscription outside Thailand’s taxing right entirely, and outside Thai withholding.
What gets left out of most of that coverage is that the ruling interprets Thailand’s tax treaties with the United States, Ireland and Hungary, not the Singapore-Thailand treaty. A Singapore seller cannot simply point to this ruling and assume it applies. The Singapore-Thailand DTA has to be read on its own terms. Under Article 12 of that treaty, royalty withholding is capped at 5 percent for copyright of literary, artistic or scientific work, 8 percent for patents, trademarks, designs and similar rights, and 10 percent for anything else classed as a royalty.4 Separately, the Singapore-Thailand DTA has no standalone technical or management fee article at all, so a cross-border service fee that is not mischaracterised as a royalty falls under Article 7, Business Profits, and Thailand has no taxing right over it without a PE.4 The practical effect for most SaaS pricing is similar to the favourable US/Ireland/Hungary reading, but you arrive there through the Singapore treaty’s own royalty and business-profits articles, not through borrowing someone else’s ruling.
Stamp duty: a court-admissibility trap, not a tax bill
Thailand’s Revenue Code Stamp Duty Schedule covers 28 specified categories of instrument.7 Hire-of-work agreements, the category most software and services contracts fall into, carry duty of 0.1 percent of the contract value, and loan agreements carry the same 0.1 percent rate, capped at THB 10,000 per instrument. Duty is generally payable within 30 days of execution, or of the document’s first arrival or use in Thailand if it was executed abroad.7
The part that catches people is not the cost. It is that an unstamped or insufficiently stamped instrument is not admissible as evidence in a Thai civil court. The underlying contract is not void, but if a Thai counterparty stops paying and you need to enforce the agreement in Thailand, an unstamped document can be turned away as evidence until the duty, plus a surcharge reported at 200 to 600 percent of the amount owed, is paid.7 A Singapore seller who signs a services agreement with a Thai customer and never thinks about stamp duty because no Thai entity is involved can still find that agreement unusable in a Thai dispute.
**The SaaS ruling's treaty scope, again, because it matters.** Gor.Kor. 0702/1626 is a specific private ruling interpreting the US, Irish and Hungarian treaties. Practitioners treat its reasoning as indicative of the Revenue Department's current approach generally, but it is not a generally binding regulation and it does not itself say anything about the Singapore treaty. Apply the Singapore-Thailand DTA's own Article 12 and Article 7 language rather than assuming this ruling covers you.
**The exact 1 September 2021 effective date and the 16 August 2021 portal opening date** for the e-Service VAT regime are widely and consistently repeated across secondary commentary, but this registry could not trace either specific date to a source we can name and cite, only to named advisors reporting it without a published URL. We have stated the regime as running "since 2021" rather than naming the exact day.
**The remittance or branch-profits tax sometimes described as applying on top of the 20 percent PE-profits CIT**, commonly cited around 10 percent with a combined effective burden of 28 to 37 percent, could not be independently verified against a primary source in this pass. Treat the 20 percent CIT exposure on PE profits as solid and the remittance add-on figure as unconfirmed.
**How much anyone is actually asking about this.** Everything in this chapter comes from tax advisory content written to attract clients, not from any evidence of Singapore SME demand for it. It is entirely possible this topic is more heavily published about than it is actually searched for. If your business does not involve software, SaaS or e-commerce sold remotely into Thailand, this chapter was very likely not written for you.
When a Thai entity becomes the better answer
The no-entity route works cleanly while your presence in Thailand stays remote and your contracts stay correctly characterised. It stops working the moment either of the PE tests above starts looking close. If you find yourself routinely staffing implementation or support work in Thailand, tracking day counts to stay under 183, or relying on a local contact who is starting to negotiate and effectively conclude deals on your behalf, you are managing PE risk instead of avoiding it, and the paperwork discipline that takes gets expensive in its own right. At that point a Thai entity, whether an ordinary company or a BOI-promoted one under the software and digital activity codes covered in BOI promotion, converts a grey-zone exposure into a known, budgetable cost. The stamp duty admissibility trap is a smaller version of the same logic: once you are relying on Thai contracts being enforceable, it is worth treating them with the same care you would give a contract signed by a Thai subsidiary.
Before you assume you can sell into Thailand without an entity
- Have you tracked, in writing, how many days your people have spent delivering services in Thailand on the same or a connected project in the trailing 12 months?
- Has your Thai revenue from non-VAT-registered customers crossed THB 1.8 million a year, and have you registered for e-Service VAT accordingly?
- Is your Thai contract correctly characterised as business profits under Article 7 rather than a royalty under Article 12, and would that classification survive scrutiny?
- Does anyone in Thailand habitually negotiate or effectively conclude contracts that you simply sign off, even if they carry no formal signing authority?
- If a Thai customer stopped paying tomorrow, is your services agreement stamped, and would it hold up as evidence in a Thai court?
- Have you checked the Singapore-Thailand treaty’s own text, rather than assuming a favourable ruling written for a different country’s treaty applies to you?
This article is one of twenty-four chapters. The complete guide adds six working tools: a registered-capital worksheet, an annual compliance calendar, an incorporation document checklist, a partner due-diligence checklist, a setup cost and timeline comparison, and a decision tree for choosing your structure.
Sources
7 sources for this article, 1 of them primary. Where we could not verify something, the article says so rather than estimating.
- Global VAT Compliance, www.globalvatcompliance.com
- HLB Thailand, www.hlbthai.com
- HLB Thailand, www.hlbthai.com
- IRAS Singapore (primary), www.iras.gov.sg
- PwC Worldwide Tax Summaries, taxsummaries.pwc.com
- PwC Worldwide Tax Summaries, taxsummaries.pwc.com
- PwC Worldwide Tax Summaries, taxsummaries.pwc.com
This article is general information about doing business in Thailand and is not legal, tax, or financial advice. Every figure is cited with its source and its date. Thai regulation is changing quickly and rules current at publication may change without notice. Confirm anything you intend to act on with qualified Thai counsel.