Once you and an HDB resale seller agree on a price, the next major step is usually the Option to Purchase (OTP).
The OTP is the HDB-prescribed legal contract that gives you the right to buy the flat at the agreed price within a fixed period. Buyers and sellers must use HDB's prescribed OTP form for the resale transaction.
But before the seller can grant you an OTP, there is one important requirement: you must already have a valid HDB Flat Eligibility (HFE) letter. HDB also requires the HFE letter to remain valid when you submit your resale application. Read more about it in our article here (link to the HFE article).
What Is the Option Fee?
When the seller grants you the OTP, you pay an Option Fee.
The amount is negotiated between buyer and seller and must be between S$1 and S$1,000. It forms part of the flat's purchase price.
Once the OTP has been granted, the seller cannot grant another OTP to another buyer until yours expires.
How Long Is the OTP Valid?
The OTP gives you a 21-calendar-day Option Period, including weekends and public holidays.
This period gives you time to confirm your financing and decide whether to proceed.
If you are using CPF savings or a housing loan, you must also submit a Request for Value through My Flat Dashboard by the next working day after the Option Date. The flat value is used as the basis for CPF usage and as a reference for the housing loan amount.
Before making an offer, buyers can also use RealValue Instant Valuation as an additional reference when comparing the asking price against surrounding properties.
What Is the Option Exercise Fee?
If you decide to proceed, you must exercise the OTP within the Option Period.
You do this by signing the Acceptance section, returning the OTP to the seller and paying the Option Exercise Fee.
The Exercise Fee is negotiated between buyer and seller, but the Option Fee and Exercise Fee combined cannot exceed S$5,000.
For example, if you paid a S$1,000 Option Fee, the Exercise Fee can be up to S$4,000.
What If You Decide Not to Buy?
If you change your mind, you can simply allow the OTP to expire.
However, you will forfeit the Option Fee you already paid. The seller can then grant a new OTP to another buyer after your OTP has expired.
What Happens After You Exercise the OTP?
Once you exercise the OTP, you and the seller have entered into the resale contract.
Both parties must then submit their respective portions of the resale application to HDB:
- Within the timeframe agreed in the OTP, and
- Within 7 calendar days of each other's submission.
HDB will review the application and supporting documents before accepting and processing the resale. HDB states that, once the application and documents are in order, the resale process generally takes about 8 weeks to complete.
The Bottom Line
The HDB OTP process can be summarised simply:
Get a valid HFE letter → agree on price → pay Option Fee → use the 21-day period to confirm financing and value → exercise the OTP and pay the Exercise Fee → submit the resale application.
The key figures to remember are:
Option Fee: S$1–S$1,000
Total Option Fee + Exercise Fee: Up to S$5,000
Option Period: 21 calendar days
Before paying the Option Fee, make sure your HFE letter is valid, your financing is clear and you are comfortable with the agreed purchase price.
Disclaimer: HDB rules and information used in this article are accurate as of 25 September 2026 and may change. Always refer to HDB's latest OTP and resale requirements before committing to a purchase.
