There is nothing explicit in the Common Law or in the Uniform Trust Code or, indeed, the Maryland Trust Code (a legislative proposal not yet enacted, see § 1.5 below) that differentiates between the professional and the non-professional trustee. The various fiduciary duties apply with equal force, in theory, to both.
At least one law professor believes that a different set of rules should be formally recognized to apply to the non-professional trustee – particularly with respect to the duties of loyalty and to delegation. Her point is that, in practice, courts have long carved out such a distinction:
Courts, with their case-specific approach to rules, intuitively understand that the identity of the trustee should make a difference in assessing liability for breach of fiduciary duty. Whether expressly or implicitly, courts gradually have developed two sets of rules. Thus, changing fiduciary standards to protect the non-professional was never really necessary
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A trustee breaches its duty of loyalty when it personally profits from transacting business with the trust. As the following sections demonstrate, the standard for determining trustee liability for such a breach should vary depending on whether the trustee is a professional or non-professional. Over time, case law has evolved to take account of this difference. A review of cases from the last decade establishes that courts generally do not hold non-professional trustees liable for self-dealing acts taken in good faith to benefit the trust. Professional trustees, however, are subject to the no further inquiry rule, which requires them to obtain advance approval prior to transacting with the trust. In the following sections, I develop an analytical framework to explain why this doctrinal development is sound.
* * *[A] significant number of trusts with non-professional trustees are family trusts that create a built-in conflict of interest between the trustee’s fiduciary obligations and personal interests. For example, a settlor may create a by-pass or credit-shelter trust, naming her spouse as trustee and income beneficiary with limited rights to principal distribution, and her children as remainderman. Or, a settlor might devise shares of a family owned corporation in trust to benefit his descendants, and name a child who controls the company as trustee with the power to vote the trust’s shares. In these situations, that the trustee will take actions that benefit herself is practically guaranteed; applying the no further inquiry rule to impose liability when the trustee does not understand the need to obtain advance approval surely would frustrate the settlor’s intent.The case can be made, then, that non-professional trustees should be judged differently than professionals when they transact with the trust without obtaining advance approval. Increasingly, courts are recognizing as much. A review of case law over the past decade establishes that not one court has removed a non-professional trustee or imposed personal liability for self-dealing without advance approval when the trustee’s self-interested transaction was a good faith attempt to benefit the trust and effectuate the settlor’s objectives. On the other hand, courts find that trustees have breached their duty of loyalty when a reasonable person should have known that the self-dealing act would not benefit the trust. Although courts are not always clear about what standard they are applying, several courts have expressly rejected beneficiaries’ arguments that the no further inquiry rule should apply to non-professional trustees.
Professor Leslie’s “proof” that courts uniformly apply a softer standard to the non-professional trustee includes a Maryland case, Helman v. Mendelson, where the Court of Special Appeals declined to remove a non-professional trustee who borrowed money from the trust because the transaction was fair and the trustee acted in good faith. In that case, the Court distinguished between the trustee/beneficiaries who made the self-dealing loans in Helman with cases where similar transactions triggered a bright line approach. The Helman Court declined to apply the no-further-inquiry rule to a non-professional trustee.
The suggestion that Helman is an example of courts applying looser standards to non-professional trustees has been challenged:
As to the application of the no further inquiry rule to amateur trustees, the cases cited by Professor Leslie in fact allow good faith to excuse self-dealing, contrary to the no further inquiry rule, where the transaction was not in fact harmful. But in each case, the court grounded the deviation on a well-recognized exception to the rule. The sampling of available reported cases is small, however, and we cannot know what is happening at the trial court level in unappealed cases.
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With respect to the amateur trustee, Professor Leslie correctly notes that when the settlor chooses a family member or friend as trustee, that selection is most likely based on factors involving that particular person’s attributes and relationships with the beneficiaries of the trust. Often, the trustee has a beneficial interest in the trust, such as in cases where an adult child is named as trustee of a trust for settlor’s surviving spouse, who may be parent of the trustee, where the adult child and her siblings are the remainder beneficiaries. The effect of the no further inquiry rule could be significantly ameliorated if courts recognized that the settlor has impliedly waived any conflicts or self-dealing prohibitions by putting a person with an interest in the trust in the position of trustee. Broadening the exceptions to the self-dealing rule to allow a good faith test where the structure of the trust indicates that such transactions would be within the settor’s intent would be more narrow than moving to a good faith test for all amateur trustees, but the latter may negate the rule in cases where the traditional justifications for the rule are still present. The rule was intended to protect the beneficiary because of the difficulty of monitoring — particularly where the beneficiary has limited capacity — and the ease with which a trustee can abuse its power over another person’s assets. 
Professor Boxx’s reading of Helman is that the Court excused the self-dealing conduct because of an exculpatory clause that imposed a good-faith exception to actionable conduct.
 Melanie B. Leslie, Common Law, Common Sense: Fiduciary Standards and Trustee Identity, 27 Cardozo L. Rev. 2713-29 (2006).