Three obstetrician-gynaecologists working in private practice in Singapore have lost their legal fight to overturn a tax ruling after authorities determined they had deliberately structured their businesses to avoid income tax. The High Court's dismissal of their challenge on June 18 represents a significant enforcement action against the medical profession and underscores the tax authority's willingness to pursue sophisticated avoidance schemes, even when challenged in court.
The three doctors—Adrian Tan Chek Jin, Caroline Khi Yu May, and Jocelyn Wong Sook Miin—had previously worked together as colleagues at KK Women's and Children's Hospital before establishing their joint private practice. Their case is particularly notable because it involved multiple corporate restructuring exercises designed to channel business profits as tax-exempt dividends and interest-free loans rather than as taxable personal income. Justice Alex Wong's written judgment explicitly noted that this case represents "the latest of several cases where medical professionals have run afoul of the tax authorities in how they have conducted the business of their medical practices," suggesting a pattern of aggressive tax planning within Singapore's medical sector.
The arrangement the three doctors created was elaborate and multifaceted. When they initially ventured into private practice in 2004, they incorporated ACJ Women's Clinic as a joint entity, with each doctor holding an equal one-third stake and drawing a monthly salary of just S$5,000. This arrangement already demonstrated the pattern that would later trigger regulatory scrutiny: despite their prior positions paying them substantially more—Tan had earned S$45,600 monthly before entering private practice—they accepted minimal salaries in their new venture.
As their practice expanded and became increasingly profitable, the doctors pursued two separate corporate restructuring exercises. The first wave saw each doctor establish individually owned medical companies between 2005 and 2007. Tan incorporated AT OG Services with his wife, Khi created CKYM Holdings as sole shareholder, and Wong established JW Medical Holdings in similar fashion. These entities were strategically designed to qualify for tax exemptions available to newly incorporated companies under Singapore's Start-Up Tax Exemption and Partial Tax Exemption schemes.
The second restructuring in March 2014 introduced surgical companies owned individually by each doctor: ACJ Tan Surgery, CKHI Surgery, and Joy Wong Surgery. This two-tier structure created a functional division whereby surgical companies would bill patients for inpatient procedures while the original clinic entity handled outpatient services. Though each doctor's employment contract specified a modest remuneration of S$6,000 monthly, the real compensation flowed through directors' fees and dividends distributed by the surgical entities, which were substantially larger and benefited from the tax exemptions available to newer corporations.
Over the six-year assessment period from 2013 to 2018, the income extraction patterns became starkly apparent. Tan, despite working as a senior physician in a profitable practice, accumulated S$5.14 million in dividends from one entity and S$2.35 million from another. Beyond dividends, he extracted approximately S$830,000 in interest-free shareholder loans from one company and up to S$2.1 million from another. Similar patterns emerged with his two colleagues, though they chose not to testify before the tax board during the formal review process.
The Inland Revenue Authority of Singapore initiated formal tax audits following the trio's attempt to strike off some of their medical companies in 2016. IRAS objected to the striking-off application and subsequently reassessed their tax positions for the entire 2013-2018 period. The authority determined that the income attributable to the doctors' professional services should be taxed in their individual names rather than filtered through corporate entities, and recalculated corporate tax liabilities by clawing back previously granted exemptions and rebates.
When the doctors appealed to Singapore's Income Tax Board of Review, their challenge was unsuccessful. They then sought judicial review in the High Court, arguing that IRAS had misapplied the Income Tax Act in disregarding their corporate arrangements. The crux of their legal argument centred on whether the tax authority was justified in invoking anti-avoidance provisions designed to counteract arrangements whose primary purpose was reducing tax liability.
Justice Wong's reasoning proved particularly damaging to the doctors' case. Regarding Tan's defence that he was new to private practice and therefore justified in accepting a low initial salary, the judge acknowledged this might "partially" explain the S$5,000 figure. However, the court found no credible explanation for why his salary remained frozen at that level as the practice grew substantially more profitable, or why accumulated profits were systematically extracted as dividends and loans rather than reflected in salary increases. The pattern suggested deliberate tax planning rather than organic business evolution.
The judge also rejected Tan's assertion that tax considerations played no role in designing the practice structure. The evidence presented—the timing of corporate formations, the alignment with tax exemption eligibility periods, and the systematic use of low-salary/high-dividend arrangements—collectively indicated that tax minimisation was a principal purpose. The other two doctors' decision not to provide testimony before the board further weakened their position, leaving the court to evaluate their conduct without their explanations.
The High Court's upholding of the Board of Review's decision carries significant implications for medical professionals and other high-earning specialists throughout Singapore and the broader Southeast Asian region who operate private practices. It establishes that merely adopting a corporate structure, even one that appears commercially legitimate, will not shield professionals from tax scrutiny if the substantive arrangements disproportionately channel income through tax-advantaged entities. The ruling suggests that tax authorities increasingly possess the tools and demonstrated willingness to reconstruct income flows when the pattern of salary restraint paired with massive dividend extraction suggests avoidance rather than legitimate business structuring.
For Malaysian practitioners and business owners, Singapore's enforcement serves as a cautionary example of regulatory attitudes toward aggressive tax planning. While Malaysia's tax regime and anti-avoidance provisions differ from Singapore's framework, the broader principle—that authorities will examine the substance of arrangements rather than merely their formal structure—applies across the region. Professional practitioners contemplating business restructuring would be well-advised to ensure their arrangements reflect genuine commercial substance and demonstrate reasonable justification for their chosen structure, not merely optimal tax outcomes.
