The Option to Purchase (OTP), Explained (2026)

Every Singapore property deal — HDB or private — pivots on one document: the Option to Purchase. It is the moment a handshake becomes a binding commitment, and the point where deposits, deadlines and legal consequences enter the picture. Yet many buyers and sellers sign it understanding only half of what it does. This guide explains what an OTP actually is, how the HDB and private versions differ, and the mistakes that cost people real money.

What an OTP actually is

An Option to Purchase is a contract in which the seller grants the buyer an exclusive right to buy the property at an agreed price, within a fixed window called the option period. In exchange, the buyer pays an option fee. During the option period, the seller is locked in: they cannot sell to anyone else or change the price. The buyer, by contrast, holds a choice — exercise the option and commit to the purchase, or walk away and forfeit the fee.

That asymmetry is the whole design. The option period exists to give the buyer time to finalise financing, valuation and legal checks before committing fully, while the option fee compensates the seller for taking the property off the market. Once the buyer exercises the option — by signing it and paying the exercise amount — both sides are bound to complete the sale.

The HDB version: prescribed and non-negotiable

For HDB resale flats, there is no drafting to argue over: HDB prescribes a standard OTP form, and it is the only contract sellers and buyers may use — side agreements that contradict it are not allowed. The key mechanics:

• Before granting: the seller must have registered an Intent to Sell on the HDB Resale Portal at least seven days earlier, and the buyer must hold a valid Eligibility Letter from HDB confirming they can buy and how they can finance it.
• Option fee: a modest sum agreed between the parties, capped by HDB — check the current cap rather than assuming a figure.
• Option period: 21 calendar days from the date the OTP is granted.
• Exercising: the buyer signs the acceptance and pays a deposit; the combined option fee and deposit are capped at a small total set by HDB.

The 21 days exist so the buyer can obtain the flat’s valuation (the Request for Value is submitted after the OTP is granted) and confirm their HDB or bank loan. Sellers should note the flip side: you may not grant overlapping OTPs to multiple buyers, and once granted, you are committed for the full period. The OTP sits in the middle of the larger resale sequence — our step-by-step guide on how to sell your HDB flat shows where it fits from the seller’s side, and buyers can see the mirror image in our resale flat buying guide.

The private property version: market convention

For private homes — condos and landed — the OTP is drafted by the seller’s lawyers rather than prescribed by a statutory board, but strong market conventions apply. The option fee is commonly around 1% of the purchase price, the option period is commonly 14 days, and exercising typically requires paying a further sum that brings the total deposit to about 5%, with the balance settled at completion, usually eight to twelve weeks later. All of these are conventions, not law — the parties can negotiate different figures, and you should read the actual document rather than assume the standard.

Because private OTPs are bespoke, the details matter more: check the completion date, what fixtures are included, whether the sale is with vacant possession or subject to tenancy, and any special conditions. This is precisely what your conveyancing lawyer is for — engage one before you sign anything, not after.

Exercising, lapsing and what each costs

To exercise an OTP, the buyer signs the acceptance within the option period and pays the exercise amount, usually through the lawyers or, for HDB, per the prescribed process. From that moment the contract is binding both ways: the buyer must complete the purchase, and stamp duty obligations are triggered — buyer’s stamp duty, and additional buyer’s stamp duty where applicable, are payable within the statutory deadline after exercising. Our stamp duty explainer covers how BSD and ABSD work and when they bite.

If the buyer lets the option lapse, the outcome is clean but costly: the seller keeps the option fee and both parties walk away. On a private deal where the fee is around 1% of the price, that is real money — which is why exercising should never depend on financing you have not yet secured. A buyer who exercises and then fails to complete faces far worse consequences, including forfeiture of the deposit and potential liability for the seller’s losses.

Timing traps to avoid

Most OTP horror stories are timing failures, not legal ones. The recurring traps:

• Signing before financing is ready. Get your in-principle loan approval, HDB Eligibility Letter or bank pre-approval before you hand over an option fee. Fourteen or twenty-one days evaporate quickly if a loan hits complications.
• Ignoring the valuation. Your loan is sized against the lower of price and valuation. If the valuation lands below your agreed price, the shortfall is cash — decide in advance whether you can cover it, or whether you would rather let the option lapse.
• Weekend and holiday maths. Option periods run in calendar days and expire at a stated time. Do not discover on a Sunday night that the deadline was Friday 4pm.
• Sellers granting an OTP too early. HDB sellers who have not completed the seven-day Intent to Sell wait, or who have not checked quota and eligibility constraints, can find their deal unravelling after commitment.
• Verbal side deals. Anything about furniture, repairs or handover dates belongs in writing within the proper documents, not in a chat thread.

OTPs in special situations

A few scenarios deserve extra care. In new launch condo purchases, the developer issues the OTP under a regime regulated for developers, with its own timelines for exercising and signing the Sale and Purchase Agreement — the rhythm differs from resale deals, so follow the developer’s and your lawyer’s schedule. In contra or concurrent sale-and-purchase situations — selling one home while buying another — the option and completion dates of the two deals must be sequenced deliberately, because a slip on one side cascades into the other. And where a buyer needs an extended option period to sort out a complex situation, that is negotiable on private deals but not on HDB’s prescribed form.

The bottom line

The Option to Purchase is a simple idea with sharp edges: a fee buys the buyer time and exclusivity, exercising binds both sides, and lapsing costs the fee. Know which version governs your deal — HDB’s prescribed 21-day form or the private market’s negotiated document — line up financing and valuation before money moves, and read every clause you sign. If you want a professional to steer your purchase or sale through the OTP stage, get matched with a licensed agent below.