Under the current IHT regime, I believe the only way an immediate IHT charge can be avoided is if the discretionary trust, or that part of the trust into which the transfer was settled, qualifies as a self-settlement trust for the disabled under s.89A IHTA 1984.
Even self-settlement into a simple life interest trust for the settlor now falls within the relevant property regime (which can pose significant issues for those UK domiciliaries working in the USA and who are being encouraged to enter into US style “living will” arrangements).
Paul Saunders