All insights

Selling guide · Family transfers

Selling property to a related party: the IRAS market value rule

By Winfred Quek, Associate Marketing Consultant · CEA R073319H · Crestbrick Pte Ltd (L31010886H) · Published 13 July 2026

Facts verified: 13 July 2026 · Stamp duty rates and rules referenced are current policy and subject to change · Sources attributed below

I get a version of this question every few months, usually from a client selling a flat or a condo unit to a sibling, an adult child, or a parent, and wanting to give them a break on price. The instinct is generous and completely understandable. The mistake I see most often is assuming that because the sale is "in the family," the taxman treats it more gently. He does not. IRAS applies the same market value test to a related party sale that it applies to a sale between two strangers, and not knowing that before you sign anything can turn a well meaning gesture into an unwelcome bill.

What IRAS actually requires when the buyer is related to you

Buyer Stamp Duty in Singapore is not calculated purely on the price written into your Sale and Purchase Agreement. It is calculated on the higher of two figures, the price actually paid, or the market value of the property at the date of the contract. For an arm's length sale between unrelated parties, those two numbers are usually close enough that the distinction barely matters, since neither side has a reason to transact away from market price. Related party sales are different precisely because there is often a reason, affection, family support, an intention to help someone onto the property ladder, and that reason is exactly what can pull the agreed price below what the market would otherwise bear.

IRAS is aware of this pattern, which is why the market value comparison exists in the first place. It protects the stamp duty base from being eroded by underpriced related party transactions, whatever the underlying motive. The rule does not stop you from helping a family member. It simply means the help has to be structured and documented rather than quietly baked into an artificially low sale price.

Why a genuine sale and a gift are taxed differently

The distinction between a sale and a gift matters more than most families realise. A sale involves consideration, meaning money genuinely changes hands, even if the amount is below market value. A gift involves no consideration at all, and is documented through a Deed of Gift rather than a Sale and Purchase Agreement. Stamp duty is still payable on a gift, assessed on market value, since there is no transacted price to compare against.

Where families run into trouble is mixing the two. Calling a transaction a "sale" at a token price that is really meant as a gift, or structuring a genuine sale with paperwork that looks like a gift, creates a mismatch between the document and the substance of the arrangement. That mismatch is precisely what invites a closer look. My separate guide on gifting property in Singapore covers the Deed of Gift route in detail if that, rather than a discounted sale, is genuinely what you intend.

How the market value assessment works in practice

When you submit a document for stamp duty, you declare the price. IRAS can accept that price, or it can form its own view of market value using recent comparable transactions, property type, location, size, and condition, much the same inputs a bank valuer would use for a mortgage. If IRAS's assessed market value is higher than your declared price, duty is charged on the higher figure, and you or the buyer will need to pay the shortfall.

This is not a theoretical risk. Recent comparable transactions for most residential property types in Singapore are a matter of public record, and a related party sale priced noticeably below recent transactions in the same block or development is an easy pattern for the system to flag. The safest position is to have your own defensible market value on file before you transact, not to wait and see what number IRAS lands on afterward.

Getting an independent valuation that protects both sides

The single most useful thing you can do before a related party sale is commission an independent valuation from a bank panel valuer or a professional valuer, dated close to the transaction. This does two things. It gives you a defensible market value figure to price against, whether you choose to sell at full value or at a documented, reasoned discount. And it creates a paper trail that shows the price was arrived at deliberately, not picked arbitrarily to minimise duty.

Where Additional Buyer Stamp Duty and Additional Conveyance Duty come in

A related party sale does not exempt the buyer from Additional Buyer Stamp Duty if they would otherwise owe it. If the buyer already owns property, ABSD applies on the same schedule as any other purchase, currently 20 percent for a Singapore citizen's second property and 30 percent for a third or subsequent property, 30 percent for a permanent resident's second property and 35 percent for a third or subsequent, and 60 percent for a foreign buyer, all assessed on the higher of price or market value in exactly the same way as Buyer Stamp Duty. If the transaction is structured through a company or trust rather than an individual, Additional Conveyance Duty can also apply on top of the usual stamp duty layers. None of this changes because the seller is a parent or a sibling. My guides on how ABSD works and Additional Conveyance Duty go into the mechanics if either applies to your situation.

Common structures families attempt, and where they go wrong

A pattern I see often is a parent wanting to sell a flat to an adult child at a nominal price, intending the difference to function as an early inheritance. The intention is fine. The execution usually goes wrong when the price is set with no reference to market value at all, sometimes literally the outstanding loan balance or the original purchase price decades earlier. Both numbers can be wildly below current market value, and both invite the exact query this article is about.

A second pattern is a sibling "buying out" a jointly inherited or co owned property at a friends and family discount, without anyone commissioning a valuation first. Because the discount was never benchmarked against an actual market figure, there is no way to demonstrate afterward that the price was a considered decision rather than an attempt to minimise duty.

How to structure it so both sides are protected

1. Get the valuation first. Commission it before you agree on a price, not after, so the price is anchored to a number rather than the other way around.
2. Decide deliberately between a sale and a gift. If the intention is genuinely to give the property, use a Deed of Gift. If the intention is a sale at a fair or discounted price, use a proper Sale and Purchase Agreement with consideration that actually changes hands.
3. Check HDB approval requirements early if applicable. Do not assume a related party transfer will be approved simply because the buyer is family.
4. Get professional conveyancing. A property lawyer experienced in related party transfers will flag ACD, ABSD, and documentation issues before they become IRAS queries.
5. Keep every document. Valuation reports, bank transfer records, and correspondence are your defence if IRAS ever asks about the pricing years later.

Frequently asked questions

Can I sell my flat to my sibling below market price?

You can agree on any price with your sibling, but stamp duty is not calculated on that agreed price. IRAS assesses Buyer Stamp Duty on whichever is higher, the price stated in the sale document or the market value at the time of sale. If you sell meaningfully below market value, duty is still charged as if the higher, market value figure had been paid, and the gap between the two can itself be treated as a gift with separate implications.

Do I need a professional valuation for a related party sale?

It is strongly advisable. An independent valuation from a bank panel valuer or professional valuer creates a documented, defensible market value at the point of transfer. Without one, IRAS forms its own view using recent comparable transactions, and if that view is higher than your transacted price, you may face a query, a revised assessment, and possibly a penalty for understated consideration.

What happens if IRAS thinks the price was understated?

IRAS can raise an assessment based on its own determination of market value. The buyer would then owe additional stamp duty on the difference, plus any late payment penalty that accrues from when duty was originally due. In cases involving a clear pattern of understatement, further penalties for incorrect stamp certificates can apply, so this is not a corner worth cutting.

Does this apply to both HDB and private property?

Yes, the market value rule applies across HDB resale flats and private property. HDB transfers carry an additional layer, since HDB must itself approve related party transfers and applies its own eligibility, occupation period, and family arrangement rules on top of the IRAS stamp duty position.

Is a related party sale the same as a gift?

No. A sale involves consideration, even if the price is below market value, and duty is assessed on the higher of price paid or market value. A gift involves no consideration and is documented through a Deed of Gift, with duty assessed on market value alone since there is no transacted price to compare. Blurring the two, calling a nominal sale a gift or the reverse, creates the exact mismatch that invites scrutiny.

Winfred Quek is Associate Marketing Consultant at Crestbrick Pte Ltd, advising Singapore upgraders, investors and families. CEA R073319H. The information on this page is general and does not constitute legal, tax or financial advice. Stamp duty, ABSD and HDB transfer rules referenced are current policy and can change; verify all figures with IRAS, HDB and a qualified conveyancing lawyer before any related party transaction.