Author and Publication
Author: Nellie Supports Ltd
Publication Date: 15/05/2026
Citation
Key v Key [2010] EWHC 408 (Ch).
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 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.
An opinion about the past, built to evidential standards
A retrospective mental capacity assessment asks whether a person had capacity for a specific decision at a specific point in the past: when a gift was made, a property transferred, an LPA signed or instructions given. The person may since have deteriorated, or died, so the opinion is constructed from records, documents and accounts rather than from a conventional visit. It is expert reconstruction, not recollection, and its value depends entirely on the rigour of the method.
When a retrospective assessment is needed
The need usually arises through dispute: a transaction challenged by family, a probate claim, a Court of Protection application examining past decisions, litigation over a settlement or contract, or a professional retracing whether instructions were validly given. It also arises protectively, where an attorney, deputy or solicitor needs the past position established before the present can be resolved. In every case the question is anchored to a particular decision and a particular date.
The test is the one that governed the decision
The applicable test travels with the decision. Most decisions engage the Mental Capacity Act 2005: understanding, retaining, using or weighing the relevant information and communicating, with any inability caused by an impairment of, or disturbance in the functioning of, the mind or brain, all assessed as at the material time. Wills engage the common law test in Banks v Goodfellow, and our guide to retrospective testamentary capacity addresses that context specifically. Identifying the right test at the right date is the first analytical step.
Subjects living and deceased
Where the person is alive, the retrospective question can sometimes be illuminated by assessing them now, because their present abilities, set against the documented course of their condition, help locate what the past position is likely to have been. Where the person has died, the record is all there is, and the discipline shifts entirely to documentary reconstruction. The report should be explicit about which situation it is in and what that means for the confidence its conclusion can carry.
How the reconstruction is conducted
The assessor defines the decision and the material dates, identifies the relevant information that decision engaged, then works through the contemporaneous record: medical and care notes around the dates, professional files and attendance notes, the person's own letters, messages and documents, and the transaction papers themselves. Witness accounts supplement the record. Each source is weighed for proximity to the material time and for the interest of its author, and the functional analysis is built from what the evidence actually shows.
Who should conduct a retrospective assessment
Retrospective work is a specialist discipline. The assessor needs command of the legal tests, experience of reasoning from records rather than presentation, and the forensic habits of provenance, dating and calibrated conclusion, because most retrospective opinions end up read adversarially. Where the opinion will be used in proceedings, it should be prepared to CPR Part 35 standards from the outset, with the expert's overriding duty to the court and the range of reasonable opinion addressed.
What a retrospective assessment can establish
Done properly, a retrospective opinion can establish the probable position on capacity at the material time, expressed with stated confidence: that the evidence supports capacity, supports incapacity or genuinely cannot resolve the question. All three are legitimate outcomes. The presumption of capacity remains the starting point, the burden of displacing it sits with those asserting incapacity, and an honest opinion locates the evidence against that framework rather than forcing a conclusion the record cannot carry.
What the report should contain
The report should identify the decision and the material dates, the test applied, every source reviewed with its date and provenance, the relevant information for the decision, the evidence bearing on each functional element, the analysis connecting any impairment to the abilities in question and a conclusion with calibrated confidence. Where the opinion is for proceedings, the CPR Part 35 apparatus, instructions, declaration and range of opinion, belongs in it from the first draft.
Key takeaway
A retrospective mental capacity assessment reconstructs a specific decision at a specific date from the contemporaneous record, under the test that governed that decision, with conclusions calibrated to what the evidence can truly bear. Commissioned early and conducted forensically, it turns an unanswerable family argument into an evidential question a court can decide.
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.