An express power of appointment conferred on a individual or, more commonly, the trustees of a trust, that enables them to direct (or redirect) given assets in favour of a particular beneficiary (or beneficiaries). The power is usually seen in discretionary trusts (where the beneficiaries do not have an automatic right to the income or capital of the trust fund), but can also be found in interest in possession (also known as life interest) trusts; it often allows the trustees to redirect the income or capital of the trust away from (or in favour of) the life tenant.

In contrast, see general power of appointment.