99-to-1 Property Purchase Singapore 2026: How Tenancy-in-Common Carve-outs Met IRAS’ ABSD Anti-Avoidance Probe
The phrase 99-to-1 Property Purchase Singapore 2026 describes a tenancy-in-common structure where one buyer holds 99 per cent of the property and a second buyer holds 1 per cent. Used legitimately, it is a perfectly valid form of co-ownership recognised under the Land Titles Act. Used as a two-step manoeuvre to add a co-owner after the original purchase, the structure became the subject of one of the most public anti-avoidance probes the Inland Revenue Authority of Singapore (IRAS) has run in the post-2010 cooling-measure era — a probe that recovered an estimated S$60 million in unpaid Additional Buyer’s Stamp Duty (ABSD) and surcharges.
This guide explains how the 99-to-1 structure works, why IRAS has scrutinised it, when a 99-to-1 split is legitimate and when it crosses the line into tax avoidance under the General Anti-Avoidance Rule (Section 33A of the Income Tax Act, with parallel application to stamp duties), and what the practical implications are for any Singapore household considering a tenancy-in-common purchase in 2026. The framework is administered by IRAS under the Stamp Duties Act, with anti-avoidance powers drawn from Section 33A of the Income Tax Act 1947.
Quick Answer — 99-to-1 in Singapore at a glance
- What it is: a tenancy-in-common (TIC) ownership split where one party holds 99 per cent and another holds 1 per cent of a single residential property.
- Why people use it: to bring a second income onto a bank loan, to plan an estate, or to manage the marital-asset split.
- Why IRAS scrutinised it: a two-step variant — Buyer A purchases 100 per cent first, then Buyer B (who already owns property) is added 1 per cent later — was used to dodge ABSD that should have applied at the higher second-property rate.
- The 2023 IRAS probe: 166 cases reviewed, an estimated S$60 million in ABSD and surcharge recovered, with a 50 per cent surcharge layered on top of the avoided tax.
- Bright-line test: if the 1 per cent share is added after the original purchase, with the only commercial reason being to avoid a higher ABSD bracket, IRAS treats it as one composite transaction and reassesses ABSD on the full price.
- Statute of limitations: up to six years backward under Section 33A.
- Legitimate use is unaffected: a 99-to-1 split applied at the OTP itself, with both parties paying ABSD on their respective shares from Day 1, is fine.
What 99-to-1 Actually Means in Singapore Property Law
Singapore property co-ownership comes in two legal forms — joint tenancy and tenancy-in-common. Joint tenancy means co-owners share an undivided 100 per cent interest, and the property passes by survivorship to the surviving joint tenant on death. Tenancy-in-common means each owner holds a defined percentage of the property, and that share passes by will (or by intestacy) on death rather than to the other co-owners. Two co-owners as tenants-in-common can hold the property in any split that adds to 100 per cent — 50/50 is the default, but 80/20, 70/30 and 99/1 are all permitted. The Land Titles Act recognises any defined share. The 99/1 split is unusual mathematically but unremarkable legally.
For stamp duty purposes, a tenancy-in-common purchase is treated as a single transaction at the property level. Each co-owner is a “buyer” under the Stamp Duties Act, and ABSD is computed against each buyer’s profile. Where the buyers fall into different ABSD brackets — for example, one with no prior Singapore property (0 per cent) and one with one prior Singapore property (20 per cent) — the rule is unambiguous: the highest ABSD rate among the joint buyers applies to the entire purchase price, not just to the higher-rate buyer’s share.
This rule is what makes the 99-to-1 split structurally different from, say, a 50-50 split. The economic exposure of the 1-per-cent owner is one one-hundredth of the property; but the ABSD effect is the same as if they owned the whole thing. The Government’s logic is straightforward — the rule is meant to plug the obvious workaround of giving a higher-rate buyer a tiny notional share to access a joint loan while ducking the corresponding ABSD.
The Two-Step Mechanic IRAS Targeted
The 99-to-1 manoeuvre that IRAS publicly scrutinised in April 2023 was not the upfront 99-to-1 split. Upfront splits, where both buyers appear on the original Option to Purchase, the Sale and Purchase Agreement and stamping documents, were never the issue — the highest-rate ABSD applies cleanly and the tax is paid in full. The structure that drew IRAS’ attention was a two-step purchase:

Step 1. Buyer A — a Singapore Citizen or Permanent Resident with no other Singapore property — exercises the Option to Purchase as the sole 100-per-cent owner of, say, a S$2 million condominium. ABSD on Buyer A is 0 per cent (or 5 per cent for a PR). Buyer’s Stamp Duty is computed normally (about S$64,600 for S$2 million). The buy is clean from the stamp-duty perspective.
Step 2. A short period later — sometimes days, sometimes weeks, occasionally a couple of months — Buyer A executes a transfer of 1 per cent of the property to Buyer B, who already owns one or more Singapore residential properties. Buyer B’s ABSD profile sits at 20, 30 or 60 per cent depending on their citizenship and prior holdings. Stamp duty would be paid on the 1-per-cent transfer at face value (BSD on S$20,000 = S$200; ABSD on S$20,000 at 20 per cent = S$4,000). The household has now achieved its real goal — both names on the title — but has paid only a fraction of the ABSD that would have been due if both names had appeared on the original OTP.
The motivation for the two-step structure is almost always financing-related. Banks underwrite home loans against the income of the named borrowers; many households need both incomes to meet the Total Debt Servicing Ratio (TDSR) cap of 55 per cent. If the higher-income borrower already owns property, putting both names on the OTP triggers the higher ABSD bracket on the entire purchase. The 99-to-1 two-step purports to achieve the loan-support outcome without the ABSD outcome.
How IRAS Pulled the Pattern Apart
IRAS announced in April 2023 that it had reviewed 166 cases of 99-to-1 (and similar structures like 95-to-5 or 90-to-10) where there was no commercial reason for the two-step pattern other than ABSD avoidance. The agency invoked Section 33A of the Income Tax Act 1947 — Singapore’s General Anti-Avoidance Rule — together with its parallel powers under the Stamp Duties Act, to recharacterise the two-step transaction as a single composite purchase. Once recharacterised, the ABSD is recalculated as if both buyers had been on the original OTP at the higher rate.

The reassessment can be material. On a S$2 million joint purchase by an SC with no prior property and an SC with one prior property, the original transaction collected ABSD only on the 1-per-cent transfer (about S$4,000). The composite reassessment applies 20 per cent ABSD to the entire S$2 million — S$400,000 — with the difference (S$396,000) recovered as additional duty. On top, IRAS imposes a 50 per cent surcharge on the avoided ABSD under the surcharge provisions of the Stamp Duties Act. Total exposure: roughly S$594,000 in additional ABSD, surcharge and interest on an originally clean-looking S$2 million buy.
The surcharge is what makes the structure so dangerous in retrospect. A buyer who would have happily paid the full ABSD upfront — perhaps deciding the higher rate was worth paying for joint-name ownership — is now exposed to half-as-much-again-on-top simply because the structure was used to sidestep it.
The Bright-Line Test — Legitimate vs Avoidance
IRAS does not publish a closed-list rule on which 99-to-1 structures are acceptable. The framework is principles-based, drawn from the long-established interpretation of Section 33A: a transaction or arrangement is voidable for tax purposes if its sole or dominant purpose is to obtain a tax advantage and there is no genuine commercial reason for it. The case law on Section 33A — including the leading Comptroller of Income Tax v AQQ decision — emphasises substance over form, intent over labels, and the natural commercial reality of what the parties actually did.

Practically, four indicators tend to push a 99-to-1 split into the legitimate column. First, both names appear on the original OTP itself — the 1 per cent is part of the original transaction, not bolted on later. Second, both parties contribute economic value proportionate to their share — for example, a child contributes a small cash deposit and is rightly entered on the title for that contribution. Third, the structure has a non-tax purpose — estate planning, succession, marital-asset planning, or a parent-and-child purchase with a real intent to leave the 1 per cent in the second name. Fourth, disclosure is clean — both parties stamp at their full ABSD rate from Day 1.
Three indicators tend to push a 99-to-1 split into the avoidance column. First, the 1-per-cent owner is added after the original purchase, with no documented commercial trigger for the late addition. Second, the only practical effect of the addition is to bring the higher-rate party’s income onto a bank loan that would otherwise not have qualified at TDSR 55 per cent. Third, the time gap between the original 100-per-cent purchase and the 1-per-cent transfer is short — days, weeks, or a small number of months — and there is no intervening event (such as a marriage, an inheritance, a job change creating a new income source) that explains the delay.
The IRAS audits in 2023 focused on cases where multiple of these markers were present together. A two-step purchase by itself is not automatically voided; what IRAS looks for is the conjunction of the markers — late addition, no commercial reason, financing motivation, short gap, and the higher-rate party already in a prior-property bracket.
What “Legitimate” Looks Like in Practice
Three real-world patterns of 99-to-1 are routinely accepted by IRAS as commercially sound and not subject to anti-avoidance recharacterisation. The first is parent-and-child estate planning: a parent buys a property and includes the child as a 1-per-cent tenant-in-common to facilitate eventual succession at fair value. The 1 per cent is part of the original OTP, ABSD is paid at the parent’s full applicable rate (with the child’s portion stamped at the child’s rate, if different), and the structure has a clear non-tax purpose.
The second is marital asset structuring before divorce: a couple in the late stages of separation may carve out a 99-to-1 split to give one party a residual interest pending the matrimonial settlement, with the larger holder having the operational control to sell. As long as the carve-out is at the OTP itself and ABSD is paid at the highest rate, this is unobjectionable.
The third is commercial co-investment with documentation: a friend-of-friend joint purchase where one party puts up the bulk of the equity and the other contributes a small share for a defined investment purpose (renovation works, future development, occupancy rights). Provided ABSD is fully paid at the highest applicable rate from Day 1, IRAS has no anti-avoidance angle to pursue.
Worked Example — Mr Lee and Mrs Lee on a S$2 Million Tampines Condo
Worked Example. Mr Lee, 36, Singapore Citizen, owns one HDB flat already. Mrs Lee, 33, Singapore Citizen, has no other property. They want to buy a S$2 million private condominium in Tampines. Mr Lee’s gross income is S$14,000 a month; Mrs Lee’s is S$5,000. Mr Lee’s prior HDB will continue to be occupied by his parents. Both names are needed on the bank loan to clear the TDSR 55 per cent test on the S$1.5 million loan they have in mind.
The legitimate joint purchase. Mr and Mrs Lee both go on the OTP as tenants-in-common at any agreed split — 50/50, 99/1, 1/99, whatever. Mr Lee falls into the 20 per cent ABSD bracket (second Singapore property). The highest-rate-wins rule applies the 20 per cent rate to the entire S$2 million purchase. ABSD = S$400,000. BSD = S$64,600. The bank underwrites the S$1.5 million loan against both incomes; TDSR clears comfortably. The Lees write the cheque, take the keys, and IRAS is satisfied.
The avoidance variant (do not do this). Mrs Lee buys 100 per cent of the condo on the OTP at S$2 million. ABSD on Mrs Lee is 0 per cent (first Singapore property). BSD = S$64,600. Six weeks later, Mr Lee is added at 1 per cent for a notional consideration of S$20,000. ABSD on the 1 per cent at his 20 per cent rate = S$4,000. The household has paid roughly S$396,000 less ABSD than it would have under the legitimate joint purchase.
The IRAS reassessment. If IRAS audits the file under Section 33A and finds the financing motivation — the bank loan was sized off both incomes from the start, and there is no commercial reason for the six-week delay other than the ABSD differential — the agency reassesses the original transaction as a composite joint purchase. ABSD becomes S$400,000. The avoided amount of approximately S$396,000 attracts a 50 per cent surcharge of S$198,000. Plus simple interest from the original stamping date to the date of the IRAS notice. Total exposure: around S$594,000 in additional duty and surcharge — most of which would have been zero if the household had simply gone on the OTP together at the start.
The arithmetic is the lesson. Households who can afford to pay the ABSD on a joint purchase should do so. Households who cannot afford it should not be using a 99-to-1 to make themselves “afford” it — the 50 per cent surcharge erases the saving and adds a felt embarrassment to the file.
Summary Table — 99-to-1 Considerations 2026
| Question | Answer (2026) |
|---|---|
| Is a 99-to-1 split itself illegal? | No. Tenancy-in-common at any defined share is recognised under the Land Titles Act. |
| Is an upfront 99-to-1 acceptable? | Yes. As long as both names are on the original OTP and ABSD is paid at the highest applicable rate. |
| Is a two-step 99-to-1 acceptable? | Only if there is a documented commercial reason for the delay. If not, IRAS may invoke Section 33A. |
| What rule applies on joint name? | Highest ABSD rate among the buyers applies to the entire purchase price. |
| Surcharge if avoidance is found? | 50 per cent surcharge on the avoided ABSD, plus simple interest from original stamping date. |
| Lookback period for IRAS | Up to six years from original stamping under Section 33A. |
| Legitimate alternatives | Decoupling (sale of one share to the other after MOP), staggered purchases over time, or paying full ABSD upfront. |
| Cases reviewed in 2023 probe | 166 cases; estimated S$60 million in ABSD and surcharge recovered. |
| Does HDB allow 99-to-1? | Generally not for HDB purchases — HDB applies its own joint-tenancy rules and prohibits decoupling since 10 April 2018. |
What This Means for You
The 99-to-1 ABSD episode is one of the clearest illustrations of how Singapore’s tax authorities use a principle-based General Anti-Avoidance Rule rather than a closed-list code. There is no specific rule banning 99-to-1 splits; there is a broader rule that any tax-driven structure with no commercial purpose can be recharacterised. Households making property co-ownership decisions in 2026 should treat this less as a single closed file and more as a continuing posture by IRAS toward stamp-duty avoidance.
The practical advice is simple. If you and a co-buyer want to be on the title, get on the title at the OTP. Pay ABSD at the highest applicable rate from Day 1. Do not invent a delayed structure to manage the bank loan unless there is a real, documentable, non-tax reason for the delay. If you are unsure whether your circumstance qualifies, consult a Singapore conveyancing solicitor before signing the OTP — restructuring is far cheaper than reassessment.
For households who genuinely cannot afford the higher ABSD bracket — for example, an upgrader couple where one spouse already owns property — the legitimate alternative is decoupling after the Minimum Occupation Period on the existing flat (if HDB, subject to the 2018 prohibition), or a staggered purchase strategy over time. These approaches respect the cooling-measure intent and do not invite the 50 per cent surcharge that attaches to recharacterised avoidance.
What Might Come Next
The 99-to-1 enforcement was a high-visibility action that has materially shifted market behaviour since 2023. Conveyancing solicitors now flag two-step structures as a matter of course; banks increasingly require ABSD payment confirmation before disbursing on transfers; and IRAS has signalled that anti-avoidance scrutiny extends to other patterns where the form of a transaction differs materially from its substance — for example, trust structures, nominee purchases, and serial divorce-and-remarriage carve-outs in property settlements.
Looking forward, two areas of policy attention deserve watching. First, the Stamp Duties Act may be tightened to make composite-transaction recharacterisation more procedurally straightforward, replacing the case-by-case Section 33A review with a clearer presumption against short-interval transfers. Second, the surcharge level — currently 50 per cent — has historical precedents at higher levels in other Singapore tax regimes, and could be revisited if avoidance patterns continue to surface. The direction of policy travel since 2010 has been toward closing perceived loopholes, not loosening them; households should plan accordingly.
Frequently Asked Questions
Is the 99-to-1 split itself illegal in Singapore?
No. Tenancy-in-common at any defined share — including 99/1 — is a recognised form of co-ownership under the Land Titles Act. What IRAS scrutinises is the two-step pattern where the 1 per cent is added after the original 100 per cent purchase, with no commercial reason other than to avoid the higher ABSD rate that would have applied if both buyers had been on the OTP from the start.
If both names are on the original OTP, do I avoid the IRAS issue?
Yes. The April 2023 IRAS probe focused exclusively on two-step transactions where the second co-owner was added later. An upfront 99-to-1 split where both names appear on the original Option to Purchase, and ABSD is paid at the highest applicable rate from Day 1, is not subject to anti-avoidance recharacterisation.
What is the IRAS surcharge if avoidance is found?
50 per cent on the additional ABSD assessed, plus simple interest from the original stamping date. On a S$2 million purchase where avoided ABSD is S$396,000, the surcharge is S$198,000 — bringing the total reassessment to roughly S$594,000 plus interest. The surcharge is what makes anti-avoidance recharacterisation economically punitive: paying upfront would have been about two-thirds of the post-audit cost.
How far back can IRAS reassess?
Up to six years from the original stamping date under Section 33A. In practice, the 2023 probe looked at transactions over the preceding several years where the two-step pattern was identifiable from records. The lookback window means structures executed in 2020–22 remained exposed when the probe was announced.
Can I do a 99-to-1 for an HDB flat?
Generally not. HDB applies its own joint-tenancy rules — most BTO and resale purchases must be in joint tenancy, not tenancy-in-common — and decoupling has been prohibited since 10 April 2018 to prevent ABSD-avoidance manoeuvres on second properties. The 99-to-1 conversation is largely confined to private property purchases.
My family bought a property in 2021 with a 99-to-1 split. Should I worry?
Read the structure carefully. If both names appeared on the original OTP and ABSD was paid at the highest applicable rate at the time, there is nothing to worry about — that is a legitimate upfront 99-to-1. If the second name was added after the original purchase and the only motivation was financing or ABSD avoidance, the file is potentially exposed under Section 33A’s six-year lookback. Consult a solicitor or tax adviser to assess the position; voluntary disclosure ahead of an audit attracts considerably more lenient treatment than reactive disclosure.
Are there legitimate alternatives that achieve a similar financing outcome?
For households where one party already owns property and the other does not, the cleanest alternatives are: (a) pay the higher ABSD rate upfront on a joint purchase; (b) execute the purchase under the non-owning party’s name with the financing structured to qualify on that party’s income alone; or (c) wait until the existing property is sold (subject to the 30-month decoupling rule for ABSD remission on a Singaporean married couple’s first new property). Each has trade-offs, but none invites a Section 33A reassessment.
Disclaimer
This article is general guidance on Singapore’s stamp-duty framework as administered by the Inland Revenue Authority of Singapore as at the publication date and is not financial, tax or legal advice. Anti-avoidance enforcement under Section 33A of the Income Tax Act 1947 and the corresponding provisions of the Stamp Duties Act is highly fact-specific; the application to any particular transaction depends on the documents, sequence and intent. For the rule that applies to your circumstances, consult IRAS, a licensed Singapore solicitor and a registered tax practitioner. Always rely on official sources — IRAS, the Stamp Duties Act and the Income Tax Act 1947 — for the latest position before transacting.









