A 99-1 ownership split is not automatically an illegal way to hold Singapore property. Two people can own a home as tenants in common in unequal shares, including 99% and 1%. The tax risk comes from how the arrangement is created, especially when a purchase is divided into separate steps to reduce Additional Buyer’s Stamp Duty (ABSD).
That difference is easy to miss. A genuine unequal ownership arrangement agreed and disclosed at the outset is not the same thing as a buyer acquiring a property alone and quickly transferring a small share to someone with a higher ABSD profile. IRAS looks at the facts and the purpose of the steps, not just the final 99-1 ratio.
What a 99-1 ownership split means
Under a tenancy in common, each co-owner has a stated share in the property. The shares may be equal or unequal. The Singapore Land Authority’s electronic transfer guidance expressly provides for tenants in common in unequal shares. A 99-1 split is one possible ratio; 80-20 or 70-30 are other examples.
The ratio affects each person’s legal interest in the property. It should not be treated as a casual entry on a form. Co-owners need to understand how sale proceeds, losses and decision-making will be handled, particularly if their cash, CPF and mortgage contributions do not follow the registered percentages. They should also discuss what happens if one owner dies, becomes bankrupt, wants to sell or stops paying the loan.
Buyers considering unequal shares should obtain conveyancing advice before signing an Option to Purchase. Our guide to disputes between Singapore property co-owners covers why a clear written agreement matters even where the buyers are spouses or close relatives.
How ABSD applies to a joint purchase
IRAS determines ABSD from the buyers’ profiles on the purchase date, including their citizenship or residency status and the number of residential properties they own. For a joint purchase by buyers with different profiles, the highest applicable ABSD rate applies to the entire property’s higher purchase price or market value.
For purchases made on or after 27 April 2023, a Singapore Citizen pays no ABSD on a first residential property, 20% on a second and 30% on a third or subsequent property. A Singapore Permanent Resident pays 5% on a first, 30% on a second and 35% on a third or subsequent property. A foreigner generally pays 60% on any residential purchase, subject to any applicable remission or free-trade-agreement treatment.
Partial ownership still counts. The IRAS ABSD guide states that any interest in a residential property is included in that buyer’s property count. Owning only 1% does not preserve a person’s status as having no property. Buyers should check the current rules and available remissions rather than relying on an old calculation. Our article on common ABSD misconceptions explains several other property-count traps.
Why the two-step 99-to-1 arrangement attracts scrutiny
The arrangement examined by IRAS typically has two transactions. First, a person with no prior property count buys the home alone. Soon afterwards, that buyer sells a small share, often 1%, to a family member who has a higher ABSD profile and may also be needed for financing. Stamp duty is then paid on the second person’s small acquired share rather than on the full value that would have been taxed if both had bought jointly from the start.
In an April 2023 parliamentary reply, the Ministry of Finance said the Commissioner of Stamp Duties may use Section 33A of the Stamp Duties Act to disregard the individual steps, assess them as one joint purchase and recover the rightful ABSD. Whether a particular arrangement is tax avoidance depends on its facts and circumstances. MOF also said there is no statutory time limit for stamp-duty audits. The full explanation is available in the parliamentary reply on 99-to-1 arrangements.
This is why the slogan “99-1 is legal” is too broad to guide a purchase. Unequal co-ownership is a recognised manner of holding property. A contrived sequence whose purpose is to avoid the ABSD due on a joint acquisition can still be challenged.
The financial consequences can extend beyond unpaid duty
If IRAS concludes that tax avoidance occurred, it can claw back the additional duty and impose a surcharge of 50% of that additional amount. Further penalties may apply if the duty and surcharge are not paid by the deadline. Giving false or misleading information during an audit creates a separate and more serious problem.
In February 2025, IRAS announced the first convictions for false and misleading information supplied during an audit of a two-step 99-to-1 transaction. A mother and son were each sentenced to two weeks’ imprisonment. IRAS said the case involved a sole purchase followed by a transfer of a 1% share, and that the stated financing explanation was false. The authority’s case statement also advises purchasers with such two-step arrangements to consider voluntary disclosure.
Separate from tax, a 1% owner is still a registered co-owner. Family expectations can change after divorce, death, financial distress or a disagreement over sale proceeds. A mortgage arrangement also does not rewrite the registered ownership shares. Buyers need legal advice on the ownership structure and lender requirements, not a spreadsheet showing only the hoped-for stamp-duty saving.
When unequal ownership may have a genuine purpose
There can be non-tax reasons for unequal shares. Buyers may contribute different amounts, wish to record different beneficial interests or need an ownership structure suited to a documented family or commercial arrangement. The mere use of 99-1 does not establish that every case is avoidance; the Government has said IRAS assesses each case on its surrounding facts.
Documentation helps explain a genuine arrangement, but paperwork cannot turn an artificial tax-avoidance plan into a commercial one. The timing of the agreements, payment trail, communications between the parties, financing discussions and advice received may all be relevant if IRAS reviews the transaction. A side agreement that conflicts with the declared ownership can create further legal and tax questions.
Checks to complete before signing
- Tell the lawyer the full plan. Disclose every intended buyer, later transfer, funding source and existing property interest before anyone exercises the option.
- Calculate the joint-purchase position first. Use the highest ABSD profile on the full property value as the starting point, then ask whether any statutory remission genuinely applies.
- Do not assume 1% is ignored. Any residential interest generally counts as one property for that person’s future ABSD profile.
- Match ownership to the real arrangement. Record contributions, responsibilities and the intended treatment of sale proceeds in documents prepared with proper legal advice.
- Keep complete records. Preserve truthful correspondence, payment records and advice. Never alter messages or invent a financing explanation for an audit.
- Review an existing two-step deal promptly. Ask a Singapore tax lawyer about the facts and whether a voluntary disclosure to IRAS is appropriate.
A 99-1 split should be chosen because it accurately records a defensible ownership arrangement, not because the ratio appears to make ABSD disappear. Before committing, buyers should get independent conveyancing and tax advice based on the complete transaction. The cost of correcting a contrived structure can be far higher than the fee for advice at the start.
