ABSD 99-to-1 Trust Loophole Singapore
How a co-ownership split meant to dodge Additional Buyer’s Stamp Duty led to a S$60 million IRAS crackdown
Last updated: September 2026
The ABSD 99-to-1 arrangement was a private property purchase structure where one buyer took a 99% share and a second buyer took a nominal 1% share, intended to let the minority co-owner later acquire a larger stake while paying Additional Buyer’s Stamp Duty (ABSD) on only the small initial slice, a practice IRAS ruled was tax avoidance in the majority of cases it audited.
Not financial advice. All figures for educational reference only. Data as at September 2026.
- Under the 99-to-1 scheme, a property is bought with a 99%/1% ownership split, then the minority owner later buys more of the 1% partner’s original share, or the pair separately trigger a decoupling exercise.
- IRAS launched an audit in April 2023 covering 187 property purchases structured this way, and found 166 of them, about 89%, to be tax avoidance rather than genuine co-ownership.
- As of May 2024, IRAS was clawing back approximately S$60 million in unpaid ABSD from these cases, on top of the ABSD that should have been paid upfront.
- Cases found to be tax avoidance face a 50% surcharge on the ABSD amount that should have been paid, a substantial additional penalty on top of the tax itself.
- The 99-to-1 structure is not automatically illegal. IRAS applies a facts-and-circumstances test, and arrangements with genuine bona fide commercial reasons unrelated to ABSD avoidance are not penalised.
Table of Contents
What Is ABSD 99-to-1 Loophole?
Additional Buyer’s Stamp Duty (ABSD) is a steep, tiered tax that Singapore imposes on the purchase of residential property, scaling up sharply for a buyer’s second, third, or subsequent property, and for foreign buyers. Because the tax is assessed on each buyer’s proportionate share of the purchase, some buyers and their advisers structured purchases so that a person who already owned property would take only a token 1% stake in a new property, while a spouse, family member, or related party with no prior property took the remaining 99% stake, minimising the ABSD payable at the point of purchase.
The plan, in many of the flagged cases, was to later have the 99% co-owner “sell” or transfer additional shares to the 1% co-owner, sometimes structured through a trust or through a subsequent decoupling transaction, effectively achieving joint ownership without ever paying ABSD on the full value at the higher rate that would have applied had both parties bought in from day one under normal proportions.
This is distinct from, but sits alongside, other Singapore property structuring mechanics such as Additional Buyer’s Stamp Duty itself and Additional Conveyance Duties on property-holding entities, both of which exist specifically to close avenues for reducing property transfer taxes through creative structuring.
How It Works in Singapore
The Inland Revenue Authority of Singapore (IRAS) began actively auditing 99-to-1 property purchases in April 2023, after noticing a pattern of unusually skewed ownership splits that had little commercial logic beyond stamp duty minimisation. Out of 187 cases reviewed, IRAS determined that 166, roughly 89%, were structured primarily to avoid ABSD rather than for any bona fide reason such as differing financing capacity or genuine unequal contribution.
IRAS applies Section 33A of the Stamp Duties Act, an anti-avoidance provision that lets the authority disregard artificial or contrived arrangements and assess duty as if the avoidance step had not taken place. In practice, this means IRAS re-assesses the transaction as though both parties had purchased their true intended shares from the outset, then bills the ABSD shortfall, plus, for tax avoidance cases, a 50% surcharge on that shortfall.
By May 2024, this exercise had recovered approximately S$60 million across the audited cases. Legal commentators have noted that whether a specific 99-to-1 arrangement survives scrutiny depends heavily on the facts: genuine reasons such as one party being unable to obtain financing, or a documented intention for the minority owner to increase their stake gradually as their finances allow, are treated differently from cases where the paperwork shows a pre-planned share transfer engineered purely to sidestep ABSD.
Worked Example
Consider a Singapore couple where one partner already owns an HDB flat (making any new private property purchase their second property, attracting 20% ABSD as a Singapore Citizen buying a second residential property) and the other partner owns no property.
Under a 99-to-1 structure, the property-owning partner takes only a 1% share of a new S$2 million condominium, paying ABSD on just S$20,000 of value, while the property-free partner takes the 99% share at the lower first-property ABSD rate (0% for a Singapore Citizen’s first property). Total ABSD paid might be a few thousand dollars, versus the tens of thousands that would apply if the ownership split reflected the couple’s actual intended joint control of the asset.
If IRAS later determines, based on loan documents, subsequent share transfers, or other evidence, that the real intention was joint ownership from the start, it can reassess ABSD as if the split had been more balanced, then add the 50% surcharge on the shortfall, potentially turning a modest stamp duty bill into a six-figure liability.
Advantages
- None, from a compliance standpoint. A 99-to-1 split entered into specifically to reduce ABSD carries real audit and penalty risk, and this glossary entry documents the mechanism precisely so investors understand why it is now closely scrutinised, not as a workaround to attempt.
- Genuine co-ownership flexibility remains legal. Couples or family members can still structure unequal shareholdings for real commercial reasons, such as one party contributing a larger down payment or having stronger loan eligibility.
- Clearer rules reduce ambiguity going forward. The 2023 to 2024 enforcement wave gives conveyancing lawyers and buyers clearer precedent on what IRAS will and will not accept.
- Legitimate decoupling remains available. Existing co-owners can still decouple, where one party sells their share to the other, to free up ABSD-free capacity for a future property purchase, provided it is not layered on top of an artificial initial split.
Risks and Limitations
- Retroactive tax assessment. IRAS can and does go back and reassess older transactions once a pattern of avoidance is identified, so buyers cannot assume time has made a scheme safe.
- 50% surcharge on top of the ABSD shortfall. This penalty alone can dwarf any stamp duty saved by the original structuring.
- Reputational and legal exposure. Cases judged to be deliberate tax avoidance, rather than a grey-area interpretation, can also attract scrutiny from conveyancing lawyers and, in egregious cases, referrals for further investigation.
- Financing complications. A 1% co-owner typically cannot use CPF or secure a meaningful home loan share against such a small stake, which itself can be evidence the arrangement was not a genuine ownership structure.
- Uncertainty for legitimate unequal splits. The crackdown has made some conveyancing lawyers more cautious about advising on any skewed ownership ratio, even when the underlying reason is legitimate, adding friction for buyers with real reasons for an unequal split.
99-to-1 Structuring vs Legitimate Decoupling
| Feature | 99-to-1 Structuring | Legitimate Decoupling |
|---|---|---|
| Purpose | Minimise ABSD via an artificially skewed initial split | Free up ABSD-free purchasing power for a future property |
| Timing | Structured at the point of initial purchase | Typically executed years after joint purchase, once equity has built up |
| IRAS treatment | Subject to Section 33A anti-avoidance review | Generally accepted if properly documented and duties paid on the transfer |
| Duties payable | ABSD potentially reassessed plus 50% surcharge if flagged | Buyer’s Stamp Duty and possibly ABSD paid transparently on the transferred share |
| Typical use case | Attempting to reduce ABSD before it is even paid | Restructuring ownership after a marriage, divorce, or investment strategy change |
The Bottom Line
For Singapore investors, the 99-to-1 episode is a reminder that IRAS actively audits property ownership structures that look engineered to avoid ABSD, and that Section 33A gives the authority real teeth to reassess duty plus a 50% surcharge years after the fact. Genuine co-ownership flexibility still exists, but it needs to be grounded in real commercial reasons, properly documented, rather than a template aimed purely at minimising stamp duty.
Related Terms:
Frequently Asked Questions
Is the 99-to-1 property ownership structure illegal in Singapore?
The structure itself is not automatically illegal. IRAS applies a facts-and-circumstances test under Section 33A of the Stamp Duties Act, treating arrangements as tax avoidance only where the primary purpose was minimising ABSD, rather than a genuine commercial reason for the unequal split.
How much has IRAS recovered from the 99-to-1 crackdown?
As of May 2024, IRAS had identified approximately S$60 million in unpaid ABSD across the audited 99-to-1 cases, after reviewing 187 transactions and finding 166 to be tax avoidance.
What penalty applies if my 99-to-1 purchase is found to be tax avoidance?
IRAS can reassess the ABSD as if the true intended ownership split had applied from the outset, and add a 50% surcharge on the resulting shortfall, a penalty that can be far larger than the stamp duty originally saved.
Can I still buy property with my spouse in unequal shares?
Yes, unequal ownership shares remain legal where there is a genuine commercial basis, such as differing down payment contributions or loan eligibility. The issue is specifically structuring around a 1% token share purely to minimise ABSD with an intention to equalise ownership later.
Does the 99-to-1 issue affect HDB flat purchases?
The scrutinised cases have mostly involved private residential property, since ABSD rates and the incentive to minimise them are more significant there. HDB flats have their own eligibility and ownership rules that make a comparable 99-to-1 structure less relevant.
How is this different from decoupling?
Decoupling happens after a joint purchase, when one co-owner sells their share to the other, and is generally accepted if duties are properly paid on the transfer. The 99-to-1 issue concerns the initial purchase structure itself, before any organic build-up of equity has occurred.
Disclaimer: This glossary entry is for educational purposes only and does not constitute financial or legal advice. Data sourced from official government and regulator sources as at September 2026.