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Author and Publication
Author: Nellie Supports Ltd
Publication Date: 15/05/2026
Citation
Key v Key [2010] EWHC 408 (Ch).
Copywright
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What is a retrospective mental capacity assessment?
A retrospective mental capacity assessment is an expert opinion on whether a person had capacity for a specific decision at a past date, formed without being able to assess them at the time, and often after the person has died. It is built from contemporaneous records, the transaction documents and witness accounts, weighed against the legal test that governed the decision: Banks v Goodfellow for wills, the Mental Capacity Act 2005 for lifetime decisions. Retrospective opinions are routine in probate disputes, contested gifts and transfers, and professional negligence claims. This guide explains what they are, how they are built and what they can and cannot say.
What this guide explains
This guide explains what is a retrospective mental capacity assessment in practical terms. The focus is not on labelling a person as capable or incapable, but on understanding the specific decision, the information that matters, and the evidence needed to support a fair and defensible conclusion.
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 decision made at the historical date, the information available then, the person’s presentation at that time, contemporaneous records and whether later evidence can reliably assist. 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 medical records, solicitor or professional notes, witness accounts, transaction documents, correspondence, care records, cognitive assessments and records created close to the relevant date. 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 retrospective Mental Capacity Assessment, 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 using hindsight, relying too heavily on later diagnosis, treating memory of events as the test, or failing to separate contemporaneous evidence from retrospective interpretation. 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
Retrospective opinions are only as strong as the evidence available. The report should explain the limits of the evidence as well as the conclusion. 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 Retrospective Mental Capacity Assessment?
Contemporaneous records are the currency: GP and hospital records around the date, care notes, solicitor files and attendance notes, banking activity and earlier documents showing the person's settled intentions. Witness recollection helps but weighs less than what was written at the time.
When is a formal assessment for Retrospective Mental Capacity Assessment useful?
Commission a retrospective opinion at the pre-action stage of a dispute: an early expert view on the strength of the capacity evidence frequently determines whether a claim or defence is worth running at all.
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.
Need an opinion on past capacity?
Nellie Supports provides retrospective capacity opinions across England and Wales for probate disputes, contested transactions and professional negligence matters, with every report peer reviewed before delivery. Call 0333 987 5118 or visit the retrospective assessment service page.