A letter of wishes is a non-binding indication by the settlor of the manner in which he wishes the trustees to exercise their discretion in relation to a discretionary trust.
Letters of wishes are normally used in testamentary trusts, although theoretically there is no reason why they should not be used in an inter vivos trust.
Letters of wishes are useful where a trust instrument gives the trustees very wide powers and discretions. The letter of wishes principally sets out the manner in which the settlor wishes the trustees to exercise their powers and discretions, but is not binding on the trustees. All binding requirements must be contained in the trust instrument itself. It is also quite common for letters of wishes to make posthumous expressions of thanks or love to the objects of the trust.