GUIDES
A retrospective opinion draws on the decision documents, contemporaneous health and professional records, the person’s own communications and witness accounts. Weight depends on relevance, reliability and proximity to the material date; no source has automatic priority in every case.
Author: Nellie Supports Ltd
Publication Date: 15/05/2026
Key v Key [2010] EWHC 408 (Ch).
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.
A retrospective opinion draws on the decision documents, contemporaneous health and professional records, the person’s own communications and witness accounts. Weight depends on relevance, reliability and proximity to the material date; no source has automatic priority in every case. This guide covers the relevant evidence, support, process and limits in England and Wales.
A retrospective opinion draws on the decision documents, contemporaneous health and professional records, the person’s own communications and witness accounts. Weight depends on relevance, reliability and proximity to the material date; no source has automatic priority in every case. Seek original records for the relevant period where lawfully available and explain omissions. A clear chronology helps distinguish observations at the time from later recollection.
A retrospective opinion is anchored to a transaction or decision, so the evidence begins with its own paperwork: the deed, will, LPA, contract or instruction, drafts that preceded it, correspondence around it and anything showing how the person participated in bringing it about. These documents fix the material dates, reveal the decision's real content and often carry the best functional evidence in the file, because the person's engagement with the transaction is visible within them.
GP and hospital records, cognitive testing, medication histories and referral letters map the impairment and its course. Their value is highest close to the material dates, where an entry can speak almost directly to the person's state at the decision, and diminishes with distance, where it speaks only to trajectory. The records should be obtained in full for the relevant period rather than summarised by an interested party, because the entries that matter are frequently the incidental ones.
Professional attendance notes may record instructions, explanations, queries and decisions close to the material time. Consider what was actually assessed, how detailed the note is and whether the professional understood the relevant question. A missing note is a gap, not proof of incapacity or professional error by itself.
Letters, emails, diaries, messages and other documents may show how the person communicated and dealt with relevant matters. Check authorship, context, date and any assistance. Competent writing about an everyday issue does not conclusively establish capacity for a different complex decision.
Witness evidence may provide important detail about the material time. Consider specificity, timing, consistency, opportunity to observe and any interest, without applying an automatic discount simply because someone is a relative or gave evidence after a dispute. Explain differences and uncertainty rather than assign a fixed hierarchy.
A current assessment, if appropriate, gives evidence of current abilities. Any inference about the past requires an evidenced account of the condition and intervening events. Good functioning today does not automatically rule out an earlier acute or fluctuating impairment, and current incapacity does not establish past incapacity.
The sources are then placed on the chronology and weighed together: proximity to the material dates, provenance, purpose of creation and consistency with one another. Convergence between independent sources, a solicitor's note, a GP entry and a granddaughter's contemporaneous text message pointing the same way, is what strong retrospective conclusions are made of. Divergence is not fatal, but it must be confronted in the analysis, not smoothed over in the summary.
List the sources, dates and provenance; identify the decision, material time and correct test; analyse relevant findings; and distinguish evidence from inference. For an MCA matter explain any causal link; for a will apply Banks v Goodfellow. Follow the applicable expert rules if the report is for proceedings and state any question the evidence cannot answer.
Use a chronology and weigh all relevant sources for reliability and relevance. Contemporaneous material is often valuable, but witness evidence or later records can also matter. A reasoned opinion explains uncertainty instead of claiming the file can reconstruct every detail.
No. A diagnosis does not establish lack of capacity. For a decision under the Mental Capacity Act, consider the relevant information and practicable support, then assess understanding, retention, use or weighing and communication by any means. Any inability must be caused by an impairment of, or disturbance in the functioning of, the mind or brain. Will-making has its own legal test.
Relevant contemporaneous health, care, professional and financial records, decision documents and witness accounts may all help. Provide material that points against the proposed conclusion as well as support, and identify gaps or uncertainty about authorship and dates.
Seek advice on whether an expert opinion would materially assist the defined question. Relevant records may take time to obtain, so identify them early; a proportionate initial review can help determine whether further work is justified.
The related guides below provide further explanation of the decisions, evidence and legal processes discussed here.
Agree the material dates and seek relevant records lawfully through the appropriate holder. Preserve originals and provenance, provide contrary evidence as well as supporting material and ask what further sources could materially change the opinion.
A GOOD PLACE TO START
Tell us what is happening and what you need help with. We will listen, explain the options and help you find the right starting point.