What is a Testamentary Trust? A testamentary trust is a form of trust that is created under the terms of a will or a codicil of a will. It comes into effect only after the death of the testator/testatrix, the person who made the Will. The trustee of a Testamentary Trust may be the executor of the deceased estate or some other person, who will be appointed by the Will. As the trustee has full control in managing the assets, careful consideration must be given to protecting the beneficiaries from dishonesty or even incompetence. However, trustees (and executors) have the duty to act with due diligence, impartially, perform the trusts honestly, in good faith, and for the benefit of the beneficiaries. “The duty of a trustee to perform the trusts honestly and in good faith for the benefit of the beneficiaries, and the same applies to executors, is the minimum necessary to give substance to...