According to a report in Zaobao, “decoupling” your HDB flat (by transferring to one owner) is no longer permitted unless there is a significant change in your family situation, e.g. divorce, death or financial difficulties.
Many people have used the “decoupling” technique to avoid paying ABSD.
For example, if John and Mary co-own a HDB flat (joint tenancy), they would previously be able to transfer the ownership to a single name — just John — so that Mary could buy a private property for investment without incurring ABSD. For a $1m condo, Mary would have saved $70k.
However, such transfers are no longer possible, unless there is a significant change in the family situation.
HDB has apparently tightened the eligibility conditions governing the transfers of flats.
[Update May 4, 2016] A day after Zaobao reported about this, Straits Times also did a similar report with some additional information. According to a HDB spokesperson, “HDB did not make the change to target the loophole that allowed buyers to avoid paying the ABSD, but as part of a regular policy review.”