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Author and Publication
Author: Nellie Supports Ltd
Publication Date: 15/05/2026
Citation
Mental Capacity Act 2005, c. 9. Available at: https://www.legislation.gov.uk/ukpga/2005/9/contents
Copywright
Copyright © 2026 Nellie Supports Ltd. All rights reserved.
This article is made available for general information, education and professional reference. It may be downloaded, printed and shared for non-commercial purposes, provided that it is reproduced in full, is not altered in any way, and is properly cited as the work of Nellie Supports Ltd. This material must not be edited, adapted, sold, republished, incorporated into commercial products, or used for commercial training, assessment, report-writing or advisory services without prior written permission from Nellie Supports Ltd.
This article does not constitute legal advice, clinical advice or a substitute for a decision-specific professional assessment. Where legislation, government guidance, court forms or external professional materials are referred to, those materials remain subject to their own copyright, licensing and re-use terms.
What duties must a trustee understand?
A trustee must broadly understand the duties the office carries: to act in accordance with the trust's terms; to act in the interests of the beneficiaries as a whole; to exercise reasonable care and skill; to avoid conflicts between personal interest and the trust; not to profit from the position; to invest and manage trust property prudently; and to keep accounts and inform beneficiaries appropriately. Capacity to act as a trustee requires broad understanding of these duties and the ability to apply them to the trust's actual decisions, not the recall of trust law chapter and verse. This guide explains each duty at the level the capacity test actually requires.
Start with the precise decision
A defensible assessment begins by recording the decision in ordinary language. In this guide, the practical question is whether the person can understand and carry out the role, responsibilities and consequences of acting as, or retiring as, a trustee. That question should shape the evidence gathered, the conversation with the person and the wording of any report.
Apply the Mental Capacity Act test to this decision
The Mental Capacity Act 2005 requires a structured approach. The person must be presumed to have capacity unless lack of capacity is established. They must be supported to make the decision where practicable, and an unwise decision is not enough on its own. The assessment then asks whether an impairment of, or disturbance in the functioning of, the mind or brain causes the person to be unable to make this decision.
Identify the relevant information
For this topic, relevant information commonly includes the nature of the trust property, fiduciary duties, the need to act for beneficiaries, conflicts of interest, record keeping, decision-making powers and the consequences of remaining in or stepping down from the role. The relevant information should be tailored to the person’s actual circumstances. It should not be copied from a generic template if the person’s options, risks or legal context are different.
Gather evidence before drawing conclusions
The assessment is stronger when the evidence is organised before the conclusion is reached. Useful evidence may include trust deeds, Land Registry information, correspondence about sale or transfer, beneficiary information, professional advice received, and any Court of Protection or Trustee Act material. Where records are missing, contradictory or out of date, the report should say so rather than overstate the certainty of the opinion.
Record practicable steps and communication support
The person should be given a meaningful opportunity to make the decision. This may involve simple language, written summaries, visual aids, additional time, breaks, support with hearing or sight, an interpreter, a familiar setting or a carefully timed appointment. The report should explain what support was tried and whether it helped.
Analyse use and weigh, not just understanding
Many capacity disputes turn on whether the person can use or weigh information, not whether they can repeat it. The assessor should consider how the person reasons through benefits, risks, alternatives and consequences. For capacity to Act as a Trustee, this means looking at the person’s own explanation and whether any impairment prevents them from weighing the material information.
Consider risk, pressure and vulnerability carefully
Risk features should be recorded without turning them into shortcuts. Common issues in this area include conflicts of interest, pressure from beneficiaries or co-owners, misunderstanding of fiduciary duties, property sale urgency and confusion between being an owner, deputy, attorney and trustee. The assessor should distinguish vulnerability, disagreement, family conflict and safeguarding concerns from evidence that the person is unable to make the decision.
What a strong report should contain
A strong report should include the instruction, the specific decision, the legal framework, the relevant information, evidence reviewed, practicable steps, direct assessment findings, functional analysis, causation and a clear conclusion. It should also explain any limitations, such as missing evidence, refusal to engage, fluctuating presentation or the need for further legal advice.
Key takeaway
Trustee capacity is legally and practically distinct from general financial capacity. A person may be able to manage ordinary money decisions but not understand trustee duties. The safest approach is disciplined and evidence-led: define the decision, tailor the relevant information, support the person, apply the functional test and explain the reasoning clearly.
Frequently asked questions
Does a diagnosis automatically mean someone lacks capacity?
No. A diagnosis may explain why capacity is in doubt, but it does not answer the legal question. The assessment must still consider the specific decision, the relevant information, the support provided and whether the person can understand, retain, use or weigh that information and communicate a decision.
What evidence is useful for Capacity to Act as a Trustee?
The trust deed and a plain account of what this trusteeship involves in practice: the assets, the beneficiaries and the decisions that recur. The assessor tests the person's grasp of the duties as they bear on those real decisions.
When is a formal assessment for Capacity to Act as a Trustee useful?
Assess formally when a trustee's grasp of their duties is genuinely doubted and decisions are pending, particularly investment changes, distributions or dealings with land, where an invalid trustee act creates problems for everyone downstream.
Related mental capacity assessment pages
These internal links help readers move from this guide to the most relevant Nellie Supports service page, assessment option or legal framework page.
Duties and capacity needing evidence?
Nellie Supports completes trustee capacity assessments across England and Wales, addressed to the trustee functions in question, with a same working day response and every report peer reviewed before delivery. Call 0333 987 5118 or visit the trustee capacity service page.