Capacity assessment: the clinical service

What a capacity assessment is

A capacity assessment is a structured clinical interview designed to establish, under the Mental Capacity Act 2005, whether a person has the capacity to make a specific decision at the time of assessment. Capacity is always:

• Decision-specific: the question is "Can this person make this specific decision?", not "Does this person have capacity in general?".
• Time-specific: capacity is assessed at the time it is in question. A person may have capacity for the same decision at a later date, or vice versa.
• Functional: the test is whether the person can understand the information, retain it, weigh it and communicate a decision, regardless of diagnosis. A diagnosis of dementia does not, by itself, mean capacity is lacking.

The underlying legal framework is the Mental Capacity Act 2005 (England and Wales), with parallel legislation in Scotland (Adults with Incapacity Act 2000) and Northern Ireland (Mental Capacity Act (Northern Ireland) 2016). See the page on the Mental Capacity Act for the legal detail.

When a formal assessment is needed

For most everyday decisions, formal capacity assessment is not required. The presumption of capacity holds, and supported decision-making is sufficient. A formal, documented capacity assessment is typically requested for:

• Testamentary capacity: capacity to make or change a Will. The test is the legal test in Banks v Goodfellow (1870), as refined by subsequent case law, applied alongside the MCA.
• Capacity to grant a Lasting Power of Attorney for property and finance, or for health and welfare. See Lasting Power of Attorney.
• Capacity to make specific financial decisions, including managing property, entering into contracts, making gifts of significant value, or signing tenancy agreements.
• Capacity to decide on residence, particularly whether to move to a care home or to a relative's home.
• Capacity to consent to a specific medical treatment, particularly significant procedures, anti-amyloid antibody therapy (Lecanemab and Donanemab) or research participation.
• Capacity to litigate: to instruct solicitors or to participate in legal proceedings.
• Capacity for sexual relationships, marriage or civil partnership.
• Capacity to make an Advance Decision to Refuse Treatment.
• Capacity in the context of safeguarding investigations or undue influence concerns.

Who can carry out a capacity assessment

Under the Mental Capacity Act, any decision-maker can in principle make a capacity judgement; in practice the complexity of the decision determines the level of professional input. The hierarchy commonly used:

• Day-to-day decisions: assessed by the person providing the care.
• Routine medical decisions: assessed by the responsible clinician.
• Significant financial, residence or treatment decisions: typically by a Consultant Psychiatrist (often in Old Age Psychiatry), a Geriatrician with capacity assessment experience, or a Clinical Psychologist.
• Testamentary capacity and complex contested cases: by a Consultant Psychiatrist with specific medico-legal experience, ideally on the GMC Specialist Register in Old Age Psychiatry, and familiar with the Banks v Goodfellow test.

Solicitors regularly commission formal capacity assessments before completing Wills, LPAs and conveyancing where capacity is in doubt. The "Golden Rule" (Kenward v Adams, 1975) recommends a medical assessment for Wills made by the elderly or seriously ill.

What the assessment involves

A formal capacity assessment is structured around the four-part functional test under the Mental Capacity Act:

1. Understanding: can the person understand the information relevant to the decision?
2. Retention: can they retain the information long enough to use it?
3. Use and weighing: can they use and weigh the information as part of the decision-making process?
4. Communication: can they communicate their decision by any means?

The assessing clinician also considers whether any impairment is due to a disturbance of the functioning of the mind or brain (the "diagnostic threshold"). The two-stage test, taken together, governs the capacity decision.

The assessment is typically conducted face to face, in private, in a setting where the person is comfortable. It usually lasts 60 to 120 minutes. Where appropriate, a corroborative history is taken separately from a close family member. The clinician applies all practical steps to support decision-making before concluding capacity is lacking.

For testamentary capacity

The Banks v Goodfellow test asks whether the person can:

• Understand the nature of making a Will and its effects;
• Understand the extent of the property of which they are disposing;
• Comprehend and appreciate the claims to which they ought to give effect;
• Be free from any disorder of mind that would influence the disposition.

A modern testamentary capacity assessment applies this test alongside the Mental Capacity Act framework, with attention to undue influence as a separate question.

What the report contains

A well-written capacity assessment report typically includes:

• The specific decision in question, defined precisely;
• The date and setting of the assessment;
• The instructing party and the purpose of the report;
• A summary of the relevant medical, social and cognitive history;
• A summary of the clinical interview, including the cognitive test result and observations on mental state;
• An analysis of each of the four functional elements of the test;
• Where appropriate, an analysis of the Banks v Goodfellow elements;
• A clear, reasoned conclusion on capacity for the specific decision;
• Where capacity is lacking, comment on whether and when it might be regained;
• Where capacity is preserved but the decision raises concerns about undue influence, comment on that separately;
• A statement of the clinician's qualifications and registration.

The Dementia Service capacity assessment

The Dementia Service, the leading UK Private Memory Clinic, offers formal capacity assessments led by Consultant Psychiatrists in Old Age Psychiatry on the GMC Specialist Register. Assessments are arranged within two to four weeks, conducted face to face or by secure video where appropriate, and produce a structured written report suitable for the instructing party (typically a solicitor or a family member, sometimes the Court of Protection). The clinical opinion is independent and disclosed in the report; the clinician is not aligned with any party to the decision.

Costs and timelines

Private capacity assessment fees in 2026 typically range from approximately £600 for a routine assessment to £2,000 or more for complex contested or testamentary cases. Court of Protection medico-legal work is charged at higher hourly rates. NHS capacity assessment for routine clinical purposes is provided as part of standard care; commissioned medico-legal assessments are not an NHS service.

Capacity assessment and Lasting Power of Attorney

The LPA process includes a Certificate Provider who confirms the donor's capacity to grant the LPA. Where there is any doubt, an independent capacity assessment by a qualified clinician strengthens the documentation and reduces the risk of later challenge. See Lasting Power of Attorney for the detail of the LPA process.

Capacity assessment and Wills

Where a person is elderly, recently bereaved, recently diagnosed with cognitive impairment, or where the new Will materially departs from a previous one, the "Golden Rule" recommends a medical capacity assessment at the time of writing. A contemporaneous, well-written report from a qualified clinician is the single most effective protection against a subsequent challenge to a Will on the grounds of incapacity.