Accepting the trusteeship is an act, and it can happen by accident. Under Montana's enactment of the Uniform Trust Code, a person designated as trustee accepts "by substantially complying with a method of acceptance provided in the terms of the trust", or, where the document provides no exclusive method, "by accepting delivery of the trust property, exercising powers or performing duties as trustee, or otherwise indicating acceptance of the trusteeship." So a designated person who starts paying bills from the trust account has accepted, whatever they told the family. The mirror rule matters just as much: a designated trustee "who does not accept the trusteeship within a reasonable time after knowing of the designation is considered to have rejected" it.
There is a narrow and genuinely useful safe harbour between the two. Without accepting, a designated trustee may act to preserve the trust property, provided they send a rejection within a reasonable time afterwards, and may inspect or investigate trust property to determine potential liability under environmental or other law. That is the provision that lets someone secure a vacant house or look at a contaminated parcel before deciding whether to take the job on.
The enumerated duties, beyond loyalty. The duty of loyalty and the voidable self-dealing transaction belong to the parent entry, which sets them out. Three further duties define the day-to-day work. Prudent administration: a trustee "shall administer the trust as a prudent person would, by considering the purposes, terms, distributional requirements, and other circumstances of the trust", and in doing so "shall exercise reasonable care, skill, and caution." Recordkeeping and separation: a trustee must keep adequate records, must keep trust property separate from their own, and must designate the property so the trust's interest appears in records maintained by someone other than the trustee or a beneficiary. Commingling is not an administrative untidiness; it is a breach of a stated duty.
The duty to inform and report is the one families are least prepared for, and in Montana's version it opens with a qualifier worth reading: the trustee must comply "unless the trust instrument specifically limits or waives any of these requirements." Subject to that, the trustee must keep qualified beneficiaries reasonably informed, notify them within 60 days of accepting the trusteeship, notify them within 60 days of learning that a trust has become irrevocable (including by the settlor's death), give advance notice of any change in the method or rate of their own compensation, and send at least annually a report of the trust property, liabilities, receipts and disbursements, "including the source and amount of the trustee's compensation." A beneficiary may waive the report, and may later withdraw the waiver.
Compensation is "reasonable", and a stated figure is not the last word. Where the terms of the trust say nothing, a trustee is entitled to compensation that is reasonable under the circumstances. Where the terms do specify an amount, the trustee is entitled to it, but a court may allow more or less if the duties turn out to be substantially different from those contemplated when the trust was created, or if the specified compensation "would be unreasonably low or high." A family member serving as trustee frequently waives the fee, and where they are also a beneficiary that is often the sensible choice, because a fee is taxable income to them while a distribution of principal generally is not.
Getting out, and being put out. A trustee may resign on at least 30 days' notice to the qualified beneficiaries, the settlor if living, and any cotrustees, or with the court's approval, and the court may impose conditions to protect the property. Critically, "any liability of a resigning trustee or of any sureties on the trustee's bond for acts or omissions of the trustee is not discharged or affected by the trustee's resignation." Removal runs the other way: the settlor, a cotrustee or a beneficiary may ask the court to remove a trustee, or the court may act on its own, on four grounds — a serious breach of trust; a lack of cooperation among cotrustees that substantially impairs administration; unfitness, unwillingness or persistent failure to administer the trust effectively and impartially; or a substantial change of circumstances or a request by all the qualified beneficiaries, where removal best serves all beneficiaries, is not inconsistent with a material purpose, and a suitable replacement is available. Only the first of those requires misconduct.
Where the authority comes from is the sharpest contrast with an executor. A trustee's powers are conferred by the trust instrument and by the trust code, and they exist from the moment the trusteeship is accepted. An executor is nominated by a will and has no authority at all until a court appoints them and issues letters. That single structural difference is why a funded trust keeps operating through a death or an incapacity while an estate waits on a courthouse calendar.