所以你要跟HDB确认你去标的BTO的时间。

http://www.hdb.gov.sg/fi10/fi10321p.nsf/w/BuyingNewFlatEligibilitytobuynewHDBflat?OpenDocument#TimeBarExistingOwner

Existing Owner or Ex-Owner of a Flat

You can apply for a flat if you, your spouse or any of the essential occupiers listed in the application is an existing owner or ex-owner of a:
flat bought directly from HDB,
resale flat bought under the CPF Housing Grant Scheme,
DBSS flat bought from the developer, or
EC bought from the developer.

This is on condition that a 5-year period (excluding any period of subletting of the whole flat) has lapsed from the *date of taking possession of the flat to the date of application for a flat.

* The date of taking possession refers to:
The date of key collection, for flats that are bought directly from HDB
The date of resale completion, for purchase of resale flats from the open market bought with the CPF Housing Grant
The date of transfer at market value of the flat bought with CPF Housing Grant
The date of key collection for Executive Condominium/DBSS flats bought from the developer, whichever is applicable.

稍微解释一下：前面是说购买任何有津贴的组屋屋主，从他拿到现有房子钥匙开始到申请下一次BTO之前，必须满足5年MOP，也就是注满5年以后才能申请BTO。

没有拿过任何津贴的二手组屋屋主，可以提前申请BTO，只要BTO拿钥匙的时间是在MOP满了之后。这个其实不用担心，因为BTO是要跟HDB直接申请的，不可以的话officer会告诉你的。