LPAs and Mental Capacity
Mental capacity is at the heart of every LPA — both in creating one and in deciding when it should be used.
Written by James Tyrrell · Reviewed by Anthony Dalton · Last reviewed
Can someone with dementia still sign an LPA? When exactly does a Health and Welfare LPA kick in? Who decides whether a person has "lost capacity"? These are questions that come up constantly, and the answers are not always obvious. The Mental Capacity Act 2005 governs all of this — when LPAs can be created, when they come into effect, and how attorneys must make decisions. Understanding how capacity works is essential for anyone creating a Lasting Power of Attorney, acting as an attorney, or caring for someone who may be losing the ability to make their own decisions.
At a glance
- You must have mental capacity at the time you sign an LPA — a diagnosis of dementia alone does not prevent this
- Capacity is assessed on a decision-by-decision basis, not as an all-or-nothing judgement
- A Health and Welfare LPA can only be used when the donor lacks capacity for the specific decision in question
- The Mental Capacity Act 2005 sets out five legally binding principles that govern every capacity assessment
The Five Principles of the Mental Capacity Act
The Mental Capacity Act 2005 establishes five core principles that underpin every decision about mental capacity. These principles are legally binding and must be followed by anyone involved in assessing capacity or making decisions on behalf of someone else:
- Principle 1: Presumption of capacity — every adult is assumed to have mental capacity unless it is established otherwise. You cannot assume someone lacks capacity based on their age, appearance, condition, or behaviour
- Principle 2: Support to make decisions — before concluding that someone lacks capacity, all practicable steps must be taken to help them make the decision themselves. This includes explaining things clearly, using appropriate communication methods, and choosing the right time and place
- Principle 3: Unwise decisions are allowed — a person is not to be treated as lacking capacity simply because they make a decision that others consider unwise. Everyone has the right to make their own choices, even if those choices seem unreasonable to others
- Principle 4: Best interests — any decision made on behalf of someone who lacks capacity must be made in their best interests. This involves considering their past and present wishes, feelings, beliefs, and values
- Principle 5: Least restrictive option — when making a decision for someone who lacks capacity, the option that least restricts their rights and freedom of action should be chosen
Key point: These five principles apply to everyone involved in the LPA process — from the certificate provider who confirms the donor's capacity, to the attorney who makes decisions on their behalf.
How Mental Capacity Is Assessed Under the Act
The Mental Capacity Act sets out a two-stage test for assessing whether someone has capacity to make a particular decision:
Stage 1: Is there an impairment of, or disturbance in, the functioning of the person's mind or brain? This could be caused by dementia, a brain injury, a mental health condition, the effects of drugs or alcohol, delirium, or any other condition that affects brain function.
Stage 2: Does that impairment or disturbance mean the person is unable to make the specific decision? A person is unable to make a decision if they cannot do one or more of the following:
- Understand the information relevant to the decision
- Retain that information long enough to use it in making the decision
- Use or weigh the information as part of the decision-making process
- Communicate their decision (by any means, including talking, sign language, or blinking)
Both stages must be satisfied for a person to be found to lack capacity. Having a diagnosis of dementia alone, for example, is not enough — it must be shown that the condition actually prevents them from making the specific decision in question.
Capacity to Create an LPA vs Capacity to Use One
There is a distinction here that matters enormously in practice:
Creating an LPA requires a relatively high level of understanding. The donor must comprehend the nature and purpose of the LPA, the scope of the powers being granted, who they are appointing, and the potential consequences. This is assessed at the time the LPA is signed, and the certificate provider must confirm they believe the donor has this capacity.
Using an LPA depends on the type. A Property and Financial Affairs LPA can be used as soon as it is registered, even while the donor still has capacity (with the donor's consent). A Health and Welfare LPA can only be used when the donor lacks capacity to make the specific health or welfare decision in question.
This distinction matters in practice. Someone in the early stages of dementia may still have capacity to create an LPA (which requires a one-off assessment), even though they are beginning to struggle with day-to-day financial decisions. This is why acting quickly is so important when cognitive decline is first noticed.
Fluctuating Capacity
Some conditions cause capacity to fluctuate. A person with early-stage dementia, for example, may have good days and bad days. Someone recovering from a brain injury may have periods of clarity interspersed with periods of confusion. Mental health conditions such as bipolar disorder or schizophrenia can also cause capacity to vary.
The Mental Capacity Act recognises fluctuating capacity. If someone has periods when they do have capacity, decisions should be delayed until a lucid period if possible. An LPA can validly be signed during a lucid period, provided the donor genuinely has capacity at that specific time.
In cases of fluctuating capacity, it is especially important to obtain a contemporaneous capacity assessment from a medical professional. This provides a documented record that the donor had capacity at the moment they signed the LPA, which protects against later challenges.
Key point: The fact that someone has fluctuating capacity does not prevent them from creating an LPA. What matters is whether they have capacity at the specific time they sign the document.
Who Assesses Capacity?
Different people assess capacity in different contexts:
- Certificate provider — when an LPA is being created, the certificate provider assesses whether the donor has capacity to understand and sign the LPA. This can be a professional (such as a doctor, solicitor, or social worker) or someone who has known the donor for at least two years
- Medical professionals — GPs, consultants, and psychiatrists may be asked to provide formal capacity assessments, particularly in borderline cases or where the LPA might be challenged
- Attorneys — once an LPA is in place, the attorney must assess whether the donor has capacity for specific decisions. For a Health and Welfare LPA, the attorney can only act when the donor lacks capacity for that particular decision
- Care professionals — nurses, social workers, and care home staff routinely assess capacity as part of their day-to-day work with vulnerable adults
- The Court of Protection — in disputed cases, the court can make a formal determination of whether someone has capacity
What If There Is a Dispute About Capacity?
Disagreements about capacity can arise at various stages. A family member might believe their relative lacks capacity to create an LPA, or an attorney might disagree with a medical professional's assessment that the donor still has capacity for certain decisions.
If a dispute cannot be resolved informally, it can be referred to the Court of Protection. The court can order a formal capacity assessment and make a binding determination. While this process can be stressful and time-consuming, it provides a clear legal answer that all parties must accept.
If someone is concerned that an LPA was made when the donor lacked capacity, they can challenge it through the OPG or the Court of Protection. Having a documented capacity assessment from the time the LPA was created provides strong evidence against such challenges.
More Guides About LPAs and Special Circumstances
How to help ageing parents put an LPA in place before it is too late When Is It Too Late to Make an LPA?
Understanding the capacity threshold and what happens if you miss the window What Happens If Someone Loses Capacity Without an LPA?
The costly and time-consuming deputyship process families face without an LPA LPAs for People Living Alone
Why an LPA is especially important if you have no partner or nearby family
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Key Takeaways
- Capacity is decision-specific — a person may lack capacity for complex financial decisions but retain capacity for everyday choices
- Fluctuating capacity does not prevent an LPA — an LPA can be signed during a lucid period, but a contemporaneous medical assessment is strongly recommended
- Unwise decisions do not mean incapacity — the Mental Capacity Act protects everyone's right to make choices others might disagree with
- Act early — someone in early-stage dementia may still have capacity to create an LPA, but this window closes as the condition progresses
- The certificate provider confirms capacity — when creating an LPA, the certificate provider assesses whether the donor understands the document they are signing
Got Questions? Here Are the Answers
Can someone with fluctuating mental capacity create a valid LPA?
Yes. The Mental Capacity Act recognises fluctuating capacity. An LPA can validly be signed during a lucid period, provided the donor genuinely has capacity at that specific time. A contemporaneous capacity assessment from a medical professional is strongly recommended in these cases.
Who decides whether a person has mental capacity?
Different people assess capacity in different contexts. When creating an LPA, the certificate provider makes the initial assessment. Medical professionals may provide formal assessments in borderline cases. In disputed cases, the Court of Protection can make a binding legal determination.
Does making an unwise decision mean someone lacks mental capacity?
No. Under the Mental Capacity Act 2005, a person is not to be treated as lacking capacity simply because they make a decision that others consider unwise. Everyone has the right to make their own choices, even if those choices seem unreasonable to others.
This guide was last reviewed and updated on . Information is based on current legislation and OPG guidance for England and Wales.
Official Guidance
Relevant government resources
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