The following is the content of Yutthana Srisavat (Ajarn Mik) from https://www.facebook.com/yutthana.srisavat/posts/pfbid0Cx4XMZYDgZ8XoEXGCdteKV8zBtgYdeiJkMFbM5wKTJeoBxPy8cCuJDRdbMPY7phbl
A summary of 19 points in the Shin Corp share tax case that dragged on for 19 years — what happened, and why the Supreme Court today ordered former Prime Minister Thaksin Shinawatra to pay a total of THB 17,629 million.
1. Shin Corporation was the company that Mr. Thaksin and Khunying Potjaman built together from 1983 (B.E. 2526). It used to be the parent company of AIS and was the largest telecommunications group in the country at that time. The company underwent several reorganizations and was recently merged with GULF on 1 April 2025 (B.E. 2568).
2. Before Thaksin ran in the 2001 election (B.E. 2544), everyone knew the basic principle that politicians must not hold businesses that could create conflicts of interest with the state — especially businesses that hold state concessions such as telecommunications.
In 1999 (B.E. 2542) Thaksin established a company called Ample Rich Investments Ltd. in the British Virgin Islands (BVI), a tax haven that keeps shareholders’ structures confidential. Thaksin’s name was the sole shareholder on paper. He then sold his Shin shares — about 33 million shares — to Ample Rich at par value, THB 10 per share. Because Thaksin realized no gain on that sale, he had no tax to pay; Ample Rich recorded the cost as nearly 33 million shares at THB 10 each.
3. In 2000 (B.E. 2543) Ample Rich’s internal structure changed so the shares were put in the name of his son (Khun Oak), who was of legal age. On paper it looked as if Thaksin no longer directly held Shin shares. As a result, when submitting his asset declarations his name did not show Ample Rich shares.
In 2001 (B.E. 2544) Shin Corp performed a share split from THB 10 par to THB 1 par, so Ample Rich’s holdings rose from 33 million to about 330 million shares, with a book cost of THB 1 per share.
By mid-2005 (B.E. 2548) Ample Rich’s shareholding was adjusted again so that the eldest daughter (Khun Aim) also held shares. The ownership then was Khun Oak 80% and Khun Aim 20%, and both served as Ample Rich directors.
4. In early 2006 (B.E. 2549), while Thaksin was still in government, the second Telecommunications Business Act was announced on 20 January 2006 to relax rules and allow foreign investors to hold up to 49% (up from 25%). That law took effect 21 January 2006.
Two days after the law took effect — on 23 January 2006 — Thaksin’s family sold about 49% of Shin Corporation on the Stock Exchange of Thailand to the Temasek-linked group from Singapore, valued at THB 73,000 million. The sale price that day was THB 49.25 per share. This was likely the first deal to immediately take advantage of the new law.
5. That share sale was tax-exempt for capital gains because the law exempted individuals selling shares through the stock exchange. So everyone who sold as individuals via the stock exchange got the full THB 73,000 million tax exemption.
6. But there was a problematic block of shares — nearly 330 million shares sold by Khun Oak and Khun Aim — because those shares had originally been held by Ample Rich since 1999. If Ample Rich had sold them, even through the stock exchange it would be taxable because Ample Rich is a company, not an individual. If the company had sold those shares, it would have been subject to withholding on the gain nearly in full: market price THB 49.25 vs. cost THB 1 per share.
7. To avoid that tax, an interposed step was used. On 23 January 2006 (the same day as the market sale), Ample Rich’s directors (Khun Oak and Khun Aim) directed the company to sell the shares to Khun Oak and Khun Aim in equal halves (50/50) at cost — THB 1 per share — in an off-market transfer.
Then, as individuals who had just acquired those shares, they sold them on the stock exchange that same day and claimed the tax-exempt status for individuals selling through the exchange.
In short, the company sold the shares at THB 1, the individuals bought and immediately sold them at THB 49.25 on the same day.
This is exactly the transaction the Supreme Court later examined: did these steps have genuine economic rationale, or were they set up solely to avoid tax?
8. From Ample Rich’s original purpose on paper — investing for profit — questions arise: how could the company sell shares at THB 49.25 by selling them at THB 1 to individuals on the same day? Why would the company effectively hand over that value for nothing?
Because no convincing investment rationale could be shown, the Revenue Department assessed that the discount — acquiring Shin shares at THB 1 when market value was THB 49.25 — was a benefit that should be valued as taxable income. The Revenue Department therefore calculated the difference (THB 48.25 per share), which amounted to a taxable income of about THB 15,883.9 million. The Revenue Department issued tax assessment notices to the individuals to settle tax for the income year 2006 (tax year 2549).
9. Khun Oak and Khun Aim contested the assessments starting at the Appeal Consideration Committee (the first administrative stage before tax court). They lost there and then went to the Central Tax Court.
While the Central Tax Court case was being heard, in 2010 (B.E. 2553) there was a separate criminal case in the Supreme Court’s panel for political office holders: the court found that the Shin shares once held by Ample Rich and then ending up with Khun Oak and Khun Aim and sold on the stock exchange were in fact owned by Thaksin himself — that Ample Rich and Khun Oak and Khun Aim were nominees for Thaksin and he was the true controlling owner.
10. In the same year, Khun Oak and Khun Aim used that Supreme Court criminal judgment to bolster their tax case: the Supreme Court had already stated the shares truly belonged to Thaksin, not to them — they were only nominees.
The tax court therefore agreed that the income should be treated as Thaksin’s income, not Oak’s or Aim’s. The tax court annulled the assessments and the appeal rulings, so Oak and Aim were relieved of tax responsibility for that matter.
The Revenue Department did not appeal further and did not issue a tax notice to Thaksin at that time.
11. After the 2010 judgment that the real owner was Thaksin, the Revenue Department could have issued an assessment to Thaksin immediately because the facts were known. But they did not. (A note: the 2010 period was the Abhisit government, and 2011 the Yingluck government.)
Time passed until 2017 (B.E. 2560), when the Prayut government advised the Revenue Department to assess Thaksin: “Hey, the fact is Thaksin was the true owner and you knew it since 2010 — so issue a retrospective personal income tax assessment for tax year 2006 from the Ample Rich–Shin share matter.”
12. Thaksin’s defense was that retroactive tax assessment is possible only within the statute of limitations, which in tax cases is at most five years. For tax year 2006 (tax returns filed in early 2007), the limitation would expire around 30 March 2012 (B.E. 2555).
Thaksin said: the Revenue Department had known since 2010 that he was the true owner because his children were litigating in tax court, but they did not issue a notice to me within the limitation period. I and my children are different persons; you could have issued me a notice earlier. To suddenly assess me now after limitation expiry — that procedure was improper.
Both the Central Tax Court and the Revenue Court of Appeal agreed that the Revenue Department made a procedural mistake at the outset: because of the flawed first step (not issuing the proper notice to the true taxpayer in time), the subsequent action was invalid. Thaksin therefore won in both lower tax courts on that ground.
13. The Revenue Department appealed all the way to the Supreme Court. In 2025 (B.E. 2568) the Supreme Court reversed the lower courts’ rulings and ruled against Thaksin, ordering him to pay THB 17,629 million.
So what happened to the earlier rulings that Thaksin won regarding the procedural misstep (no notice in time)? How did the Supreme Court reason?
14. The Supreme Court held that the nominees (Oak and Aim) were mere puppets for Thaksin, and Thaksin was the principal. Therefore, when the initial notices were sent to the nominees, those notices also “bound” Thaksin as the principal — there was no need to send a separate notice in Thaksin’s name.
The Court reasoned that because the notice was properly sent to Thaksin’s agents (the nominees), it effectively reached and bound Thaksin the principal.
15. The Supreme Court added (in a didactic tone) that establishing a BVI company, parking shares there, controlling shares via son and daughter, selling shares from the company to son/daughter at THB 1 and then selling on the stock exchange to obtain tax exemption — such transactions lacked any genuine “economic reason” other than to get a benefit and avoid tax. That is a serious moral failing in tax conduct. If such schemes were permitted, they could become a societal model used to claim tax advantages for private gain and would be unfair to ordinary citizens who honestly pay their taxes.
In short, the Court accepted the Revenue Department’s assessment. Thaksin lost at the Supreme Court level and must pay tax, penalties and interest totaling THB 17,629 million. The judgment is final.
16. Where did the THB 17,629 million come from? It is built from three components:
(1) Tax: computed on the gain base of THB 15,883.9 million. The top personal income tax rate in 2006 was 37% (not 35% as it is today), so tax is roughly THB 5,877 million.
(2) Penalty: imposed for underpayment — a penalty equal to 1× the tax due (i.e., the penalty equals the tax owing), so about THB 5,877 million.
(3) Surtax/interest for late payment: like interest on late tax payment, normally set at 1.5% per month; because many years passed the amounts compound up to a statutory cap which equals the tax due — another about THB 5,877 million.
The three parts together — tax + penalty + late interest — sum to THB 17,629 million.
So the realized gain was THB 15,883.9 million, but the tax bill became THB 17,629 million — the taxes and charges exceeded the profit.
17. Where will Thaksin get the THB 17,629 million to pay?
Of course this is a huge sum. If you built government office buildings with it, you could construct eight new SAI (or State Audit) towers and still have change left. The enforcement and collection of this tax is again the Revenue Department’s responsibility.
Typically Thaksin must pay the assessed amount; he may negotiate a reduction in penalties with the Revenue Department and may request installments for payment. The schedule and installment amounts are handled by internal Revenue Department procedures.
If Thaksin refuses to pay, the process goes to seizure and attachment of assets to satisfy the tax debt. If assets are overseas, Thai authorities may seek cooperation to seize offshore assets.
18. This Supreme Court judgment establishes a new foundation: tax planning is permitted so long as there are defensible economic reasons to support it. But where there is no other apparent intention than tax avoidance, the Court will look through the transactions to their substance. This principle is academically called the General Anti-Avoidance Rule (GAAR).
GAAR is used in many countries — Canada, Australia, China, Germany, India, among others. Academically, it’s interesting to consider whether this Supreme Court decision marks Thailand’s acceptance of GAAR in tax adjudication. If so, aggressive tax planning by the wealthy may become much riskier and require rethinking.
19. What do Thais get from this?
At least one comforting thing: the Court still recognizes the right to do tax planning. No law requires us to pay more tax than necessary. The boundary is that planning must remain on the “white” side — not gray. From now on, if planning is gray and lacks other purposes besides tax avoidance, it will likely be difficult to survive in court.
We will continue to debate what “tax planning without losing tax morality” should look like and whether the standard should apply equally to all people and families.
I also think of Dr. Suwan Walaesetthien (father of Dew Weerawat Walaesetthien), who was the tax planner for the Shin Corp deal for Thaksin. If he were still alive, we would be able to hear his perspective on whether that tax planning had tax morality and whether the Court’s decision was appropriate.
This case is one of the most important tax judgments in Thai history and will likely be a precedent shaping anti-tax-avoidance cases for many decades.