It often starts with something small. Your mum forgets where she put her keys. Your dad asks the same question three times in one afternoon. Then comes the diagnosis — dementia — and suddenly a wave of practical worries crashes in alongside the emotional ones. Who will manage their finances? Who will make decisions about their care if they can't?
If you're reading this, chances are someone you love has been diagnosed with dementia, and you're wondering whether it's too late to set up a Lasting Power of Attorney. The honest answer is: it depends. It depends on something very specific — whether your parent still has what the law calls "mental capacity."
This guide will walk you through what that means, what your options are, and what happens if the window has already closed. We'll be straightforward with you, because you deserve clarity at a time when everything feels uncertain.
What Is Mental Capacity, and Why Does It Matter?
A Lasting Power of Attorney (LPA) is a legal document. To create one, your parent must be able to understand what they're signing and why. This isn't about whether they can recite the date or name the Prime Minister. It's about whether they can grasp the nature and consequences of the LPA itself.
The legal framework comes from the Mental Capacity Act 2005, which governs how capacity is assessed in England and Wales. The Act establishes two crucial principles that work in your parent's favour:
- A person is assumed to have capacity unless it is established otherwise. A dementia diagnosis alone does not automatically mean someone lacks capacity. The starting point is always that your parent can make their own decisions.
- A person must be given all practicable help to make a decision before being treated as unable to do so. This means choosing the right time of day, using clear language, and giving your parent the support they need to understand what's being discussed.
These principles exist because dementia is not a light switch. It's a spectrum, and many people in the early and even moderate stages retain enough understanding to make valid legal decisions — including setting up an LPA.
The Capacity Test for an LPA
To have the mental capacity to create an LPA, your parent must be able to understand four things at the time of signing:
- What an LPA is and what it does. They need to understand that they are giving someone else the legal authority to make decisions on their behalf.
- Why they might need one. They should grasp that there may come a time when they cannot make these decisions themselves.
- Who they are appointing as their attorney(s). They should know who they're choosing and understand that this person will have significant power over their affairs.
- That they can set conditions or restrictions. They should understand they have the option to limit what their attorney can do.
This assessment is "decision-specific" and "time-specific." Your parent doesn't need to understand complex financial markets or recite legal terminology. They need to understand this particular decision at this particular moment.
A solicitor, GP, or other qualified professional will typically carry out or support this assessment. If there's any doubt, a formal capacity assessment can be arranged — and having one on record actually strengthens the LPA against any future challenges.
What If They Still Have Good Days?
Dementia is rarely a straight line downward. Many people experience what's known as fluctuating capacity — days when they're sharp, engaged, and clearly understanding what's going on, followed by days when confusion takes hold.
The good news is that the law accounts for this. If your parent has periods of clarity where they meet the capacity test, an LPA can be validly created during one of those windows. The Mental Capacity Act specifically states that capacity should be assessed at the time the decision needs to be made — not on their worst day.
In practice, this means:
- Choose the time of day when your parent is most alert (for many people with dementia, this is the morning).
- Make sure the environment is calm, familiar, and free from distractions.
- Explain things in simple, clear terms — and give them time to process.
- Consider having a GP or solicitor assess capacity on a "good day" and document their findings.
A signed note from a medical professional confirming that your parent had capacity at the time of signing can be invaluable. It provides a safeguard if anyone later questions whether the LPA was valid.
What Happens If It Really Is Too Late?
If your parent's dementia has progressed to the point where they can no longer understand what an LPA is — even on their best days — then it is, sadly, too late to create one. An LPA signed without capacity is invalid, and the Office of the Public Guardian will reject it.
But that doesn't mean nothing can be done. It means taking a different, more difficult path: the Court of Protection.
Deputyship Through the Court of Protection
When someone lacks the capacity to make an LPA, a family member (or sometimes a professional) can apply to the Court of Protection to be appointed as their deputy. A deputy has similar powers to an attorney under an LPA, but the process to get there is fundamentally different.
Here's what you need to know about deputyship:
- It's expensive. Court fees, legal costs, and ongoing supervision charges can easily run into thousands of pounds. The application fee alone is £371, and you'll typically need a solicitor to handle the paperwork, adding £1,000 to £3,000 or more. There are also annual supervision fees once you're appointed.
- It's slow. The application process typically takes several months — sometimes six months or longer. During that time, nobody may have the legal authority to manage your parent's finances or make key care decisions.
- It's restrictive. Deputies face more oversight than LPA attorneys. You may need court permission for certain decisions, must file annual reports, and are subject to ongoing supervision by the Office of the Public Guardian.
- The court decides, not your parent. Unlike an LPA — where your parent chooses who they trust — the court decides who to appoint. Usually it's a close family member, but not always. And if family members disagree, the process becomes even longer and more costly.
To put it bluntly: an LPA costs a fraction of what deputyship costs, takes weeks rather than months, and gives your parent the dignity of choosing for themselves. Deputyship is the safety net, but it's one nobody wants to fall into.
Early-Stage Dementia: The Window Is Open — Act Now
If your parent has recently been diagnosed or is in the early stages of dementia, this is the single most important thing you can do: set up an LPA now. Not next month. Not after Christmas. Now.
Dementia is progressive. The capacity that exists today may not be there in six months. Every week of delay is a week closer to the point where the option is no longer available. We've spoken to too many families who said, "We kept meaning to get round to it," only to find they'd waited too long.
An early-stage diagnosis is not a barrier to creating an LPA — in many ways, it's the prompt to act. Your parent can still have their say in who they want to look after their affairs and their wellbeing. That sense of control matters enormously, both legally and emotionally.
Many GPs and dementia specialists actively encourage families to arrange LPAs as soon as possible after diagnosis. Some memory clinics even raise it at the point of diagnosis because they know how critical the timing is.
The Two Types of LPA You Need to Know About
There are two separate types of Lasting Power of Attorney, and most families benefit from setting up both:
1. Property and Financial Affairs LPA
This gives your chosen attorney the authority to manage your parent's money, property, bills, bank accounts, investments, and financial decisions. It can be used while your parent still has capacity (with their permission) or after they lose it. This is often the most urgently needed LPA, because bills don't stop when someone can no longer manage them.
2. Health and Welfare LPA
This covers decisions about your parent's medical treatment, care arrangements, daily routine, diet, and — if specified — life-sustaining treatment. Unlike the financial LPA, this one can only be used once your parent lacks the capacity to make these decisions themselves. It ensures that someone your parent trusts is making these deeply personal choices on their behalf, guided by their known wishes and values.
Both types must be registered with the Office of the Public Guardian before they can be used. Registration currently takes several weeks, which is another reason not to delay — even after signing, there's a waiting period before the LPA becomes active.
The Emotional Side: Having the Conversation
We can talk about legal tests and court fees all day, but let's be honest about what makes this so hard. It's not the paperwork. It's the conversation.
Asking a parent to think about a time when they can't manage their own affairs — when they might not recognise you, when they'll need someone else to decide whether they go into a care home — is one of the most difficult conversations a family can have. It can feel like you're giving up on them, or worse, that you're after something.
But here's what families tell us after they've done it: it felt like a relief. For the parent, because they know someone they trust will be looking out for them. For the children, because they know they have the legal authority to help when the time comes, without a court battle.
A few things that can help:
- Frame it as something everyone should do — because they should. LPAs aren't just for people with dementia. Say something like, "We've been thinking about doing this for ourselves too."
- Focus on their wishes. Ask what matters to them. Where would they want to live? Who do they trust? What would they want if they were seriously ill? Make it about honouring their voice, not taking it away.
- Don't rush it. Have the conversation over a cup of tea, not in a hospital corridor. Let them sit with the idea. Come back to it if needed.
- Involve them in choosing their attorneys. This is their decision. Giving them that agency is part of why doing it early matters so much.
If your parent is resistant, that's okay. It's a lot to take in. But gently returning to the topic — perhaps with the support of a trusted family friend, their GP, or a solicitor who handles these conversations sensitively — can make all the difference.
Don't Wait for a Crisis
The families who struggle most are the ones who come to us after the crisis has already hit — after their parent has been hospitalised, after the bank has frozen the account, after a care home needs a decision and nobody has the legal authority to make it. At that point, the only option is the Court of Protection: expensive, slow, and entirely avoidable.
If your parent has dementia and still has periods of clarity, the window may still be open. But it won't stay open forever. An LPA set up today — properly, with a capacity assessment on record — protects your parent's wishes and saves your family from months of legal and financial stress down the line.
You don't need to have all the answers right now. You just need to take the first step.