Mental Capacity Assessment in Wales — Who Decides, How It Works, and Your Rights
What the Mental Capacity Act 2005 Requires
The Mental Capacity Act 2005 applies equally across England and Wales. It establishes five statutory principles, and the first one matters most for families: a person is assumed to have capacity unless it is established that they do not. No one can be treated as lacking capacity simply because of their age, appearance, medical diagnosis, or a decision that others consider unwise.
Capacity is assessed per decision, per moment. Someone can lack capacity to manage a complex property sale while retaining full capacity to decide where they live or what they eat. A person with fluctuating conditions — early dementia, brain injuries, certain psychiatric illnesses — may have capacity on some days and not others.
The Two-Stage Test
Every capacity assessment follows two questions:
Stage 1 — Is there an impairment or disturbance of the mind or brain? This includes dementia, brain injury, stroke effects, learning disabilities, mental health conditions, delirium, or the effects of alcohol or drugs. A confirmed diagnosis satisfies this stage, but a diagnosis alone does not mean the person lacks capacity.
Stage 2 — Does that impairment mean the person cannot make the specific decision? To have capacity, the person must be able to:
- Understand the information relevant to the decision
- Retain that information long enough to make the decision
- Use or weigh the information as part of the decision-making process
- Communicate the decision (by any means — speech, writing, sign language, blinking)
If the person fails any one of these four criteria because of the impairment identified in Stage 1, they lack capacity for that particular decision.
Who Carries Out the Assessment
There is no single "capacity assessor" role. The person who assesses capacity is whoever needs to make the decision at hand:
- A GP or hospital consultant assesses capacity for medical treatment decisions
- A social worker assesses capacity for care placement or safeguarding decisions
- A solicitor assesses capacity for legal transactions (signing a will, an LPA, a property contract)
- A bank manager may assess capacity for financial transactions
For LPA purposes, the certificate provider performs a practical capacity assessment when the donor signs. This is not a formal medical examination — it is a structured conversation to confirm the donor understands the document.
In complex or disputed cases, a formal assessment by a psychiatrist, clinical psychologist, or specialist GP may be requested, particularly if the Court of Protection is involved.
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Wales-Specific Safeguards
While the capacity test itself is identical in England and Wales, the welfare framework around it differs. The Social Services and Well-being (Wales) Act 2014 gives Welsh local authorities specific duties:
- Welsh local authorities have safeguarding duties under the Social Services and Well-being (Wales) Act 2014 for adults who may be at risk
- Wales operates Adult Protection and Support Orders (APSOs) under Section 127 — a Wales-only power allowing a local authority officer and police constable to enter premises to speak privately with a vulnerable adult suspected of being under coercive control
These safeguards sit alongside the Court of Protection, which handles deputyship applications for anyone who has lost capacity without a registered LPA or valid EPA.
Challenging a Capacity Decision
If you believe a capacity assessment was wrong — your parent was assessed as lacking capacity but you believe they still understand the relevant decisions — you can:
- Request a reassessment by a different practitioner
- Ask the person's GP to provide a written opinion
- Apply to the Court of Protection for a formal declaration of capacity
The key evidence is usually the two-stage test: was the impairment properly identified, and did the assessor genuinely test all four criteria rather than making assumptions based on the diagnosis alone?
The Wales Capacity Protection Toolkit covers the capacity assessment process in detail, including how to prepare a donor for the certificate provider's evaluation and how to document capacity for borderline cases.
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