By The Address desk · Last verified 28 September 2026
Buying a resale HDB flat runs on HDB’s own Option to Purchase (OTP). Once you and the seller agree a price, the seller grants you the OTP and you pay an option fee of S$1 to S$1,000. You then have 21 calendar days, ending at 4pm, to decide. If you go ahead, you pay an option exercise fee; the two fees together can’t exceed S$5,000, and they count towards the price. After that, buyer and seller submit the resale application, and completion follows about eight weeks after HDB accepts it. You need a valid HFE letter before you get the OTP.
Quick facts
- Option fee: S$1 to S$1,000, paid when the OTP is granted.
- Option period: 21 calendar days, ending at 4pm.
- Option fee plus exercise fee: at most S$5,000, and part of the price.
- Request HDB’s valuation by the next working day if using CPF or a loan.
- Buyer and seller submit resale applications within seven days of each other.
- Completion: about eight weeks after HDB accepts the application.
What are the steps?
- Get your HFE letter. It confirms your eligibility, grants and HDB loan.
- Agree a price. The seller must have registered an Intent to Sell at least seven days earlier.
- Receive the OTP and pay the option fee. From then, the seller can’t sell to anyone else during the option period.
- Request HDB’s valuation by the next working day if you’re using CPF or a loan.
- Exercise the OTP within 21 days by signing and paying the exercise fee, or let it lapse and lose the option fee.
- Submit the resale application. Buyer and seller each submit within seven days of each other.
- Complete. Endorse the documents, pay the fees, and collect the keys at completion.
Why does the valuation matter?
Because your loan is based on the price or HDB’s valuation, whichever is lower. If you agree to pay more than the valuation, the difference, often called cash over valuation, must be paid in cash.
What else will I pay?
Buyer’s stamp duty, within 14 days of exercising the OTP, which CPF can pay; legal fees; and, at completion, the seller’s share of property tax for the rest of the year.
The WahLiao Verdict
The 21 days are for checking, not deciding on impulse. Request the valuation at once, confirm your loan, and only then exercise. Once you exercise, the contract binds you, and backing out can cost far more than S$5,000.
Questions people ask
Can the option fee be zero?
No. Neither the option fee nor the exercise fee can be S$0.
What happens if I don’t exercise the OTP?
It expires and the seller keeps the option fee.
Do I need an agent?
No. The process can be done yourself through HDB’s portal, though many buyers use one.
Can I use a different OTP form?
No. HDB’s prescribed OTP must be used; other side agreements aren’t valid under the Housing and Development Act.
Sources: HDB, Option to Purchase and resale terms and conditions; PropertyGuru, buying a resale flat step by step; Little Big Red Dot on the resale timeline; Propseller on stamp duty timing. This is general information, not legal advice.
Read next: HDB Loan or Bank Loan · HDB Housing Grants · Back to The Address
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