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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.
Who can conduct a testamentary assessment?
A testamentary capacity assessment can be conducted by a range of suitably experienced professionals, including specialist social workers, psychologists, psychiatrists and doctors. No statute reserves the role to medical practitioners: what matters is competence in the Banks v Goodfellow test, skill in structured capacity assessment, strong report writing and independence from the outcome. Where a will may later be contested, the golden rule encourages solicitors to involve an appropriate professional assessor, and courts weigh the quality of the reasoning over the assessor's job title. This guide explains the options, when specialist input matters and what to look for in an assessor.
There is no single profession for every case
Testamentary capacity may be considered by a solicitor taking will instructions, a medical practitioner, a suitably experienced mental capacity assessor or another appropriately qualified professional. What matters is whether the person conducting or contributing to the assessment understands the legal test, the person’s circumstances, the relevant evidence and the purpose for which the opinion is needed.
Apply the right legal test
The key test for will-making is usually Banks v Goodfellow. The assessor should understand the nature and effect of making a will, the extent of the estate, the claims of potential beneficiaries and whether any disorder of the mind affects the will decision. A Mental Capacity Act style structure can help the reasoning, but testamentary capacity should not be reduced to a generic financial capacity assessment.
Solicitors and assessors often have different roles
A solicitor usually advises on the will, takes instructions and considers whether a capacity opinion is needed. A specialist assessor may provide an independent opinion on capacity, particularly where there is diagnosis, vulnerability, dispute, fluctuating presentation, communication difficulty or suspected pressure. In complex cases, the roles should be clearly defined in the letter of instruction.
Professional competence matters more than job title alone
A useful testamentary assessment should be completed by someone who can apply the relevant legal framework, identify the correct information, review documents, communicate effectively with the person and write a reasoned report. The assessor should also recognise limitations and recommend legal or medical input where the case requires it.
When a specialist assessor is particularly important
Specialist assessment is usually more important where the estate is valuable or complex, the person has cognitive impairment, there are allegations of coercion, the will departs from previous wishes, close relatives are excluded, or the opinion may later be relied on in contentious probate proceedings.
Independence and conflict checks are essential
The assessor should be independent of the proposed beneficiaries, should understand who is instructing them and should record any potential conflict. Where family members disagree, independence and transparent evidence handling are particularly important.
The instruction should define the task
A good instruction should state whether the assessment is prospective, contemporaneous or retrospective, whether a new will or codicil is being considered, what estate information is available, who may benefit, who may be excluded and whether concerns about undue influence or coercion exist.
What a competent report should include
A competent report should set out the decision, the legal framework, evidence reviewed, support provided, direct observations, the person’s own explanation, functional analysis, limitations and conclusion. It should be written so that a solicitor or court can understand how the opinion was reached.
Key takeaway
The right person to conduct a testamentary assessment depends on the risk, purpose and complexity of the case. For low-risk cases, a solicitor’s careful attendance note may be enough. For contested, high-value, complex or vulnerable cases, an independent specialist assessment is often safer.
Frequently asked questions
Can a GP conduct a testamentary assessment?
A GP may be involved, especially where medical history is relevant, but a brief medical letter may not be enough in a disputed will case. The key issue is whether the opinion applies the correct testamentary capacity test and explains the reasoning clearly.
Can a social worker conduct a testamentary capacity assessment?
A suitably experienced social worker or mental capacity assessor may be able to provide a structured capacity opinion, especially where social, family, communication and vulnerability factors are central. The instruction should make clear the legal test, documents to review and intended use of the report.
Does the solicitor always assess capacity themselves?
The solicitor may assess whether they can take instructions and may identify capacity concerns, but they may also seek an independent capacity opinion where the case is complex, disputed, medically uncertain or likely to be challenged.
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.
Looking for a testamentary capacity assessor?
Nellie Supports completes testamentary capacity assessments across England and Wales, prospective, contemporaneous and retrospective, through a permanent employed team with every report peer reviewed before delivery. Call 0333 987 5118 or visit the testamentary capacity assessment service page.