Third-Party Mandate, Joint Account or LPA?

By Matt Cresswell, Founder of Power of Attorney Online and author of
Everything you ever wanted to know about LPAs (but were afraid to ask)

17th August 2026

If you are helping an ageing parent with their finances, Third-Party Mandate, Joint Account or LPA? is a useful question to ask before simply adding your name to their bank account. The three arrangements can look similar from the outside, but they give you very different rights and behave very differently if your parent loses mental capacity. A third-party mandate can be useful for everyday banking while someone still has capacity. A joint account gives both account holders access to the money, but it changes the legal and practical relationship with the funds. A Property and Financial Affairs Lasting Power of Attorney, or LPA, is the more comprehensive arrangement when the intention is to make sure someone can continue managing another person’s finances if they can no longer make those decisions themselves. The right choice depends on what help is actually needed, and when.

That distinction matters more than many families realise.

A common situation is a son or daughter who starts helping a parent with shopping, bills or online banking. The parent still makes their own decisions, but managing everything themselves is becoming inconvenient.

The family then asks the bank about adding the child’s name to the account.

Sometimes that is perfectly reasonable. Sometimes it creates a much bigger arrangement than the family intended. And sometimes the family discovers the problem only when the parent becomes seriously ill and the bank can no longer simply rely on the informal arrangement.

The three ways banks let you help

There is no single “best” way to help someone with their banking. The right arrangement depends on whether you are providing convenience, sharing ownership or preparing for future incapacity.

Arrangement	What it is mainly for	If the parent loses capacity	Who controls the money?
Third-party mandate	Everyday banking help	Not generally suitable as a capacity solution	Parent remains account holder
Joint account	Shared access and ownership of an account	Bank may restrict the account depending on circumstances	Both account holders
Property and Financial Affairs LPA	Ongoing authority over another person’s finances	Designed to continue when capacity is lost	Attorney acts for the parent

A third-party mandate is essentially an instruction from the account holder to the bank allowing a named person to operate the account. Government guidance says it can be appropriate where someone has mental capacity but wants help with their banking. It specifically warns that a third-party mandate is not appropriate where the account holder is losing the ability to make the relevant decisions.

That makes it useful, but limited.

A joint account is different because the second person is not simply acting as an authorised representative. They are an account holder in their own right.

That can make everyday banking very easy. It can also create complications that families do not necessarily anticipate.

An LPA is different again. The donor chooses an attorney to make property and financial decisions on their behalf. Once the LPA is registered, the attorney can deal with matters such as bank accounts, bills, pensions, benefits, investments and property, subject to the donor’s authority and the attorney’s legal duties.

The key point is that an LPA is about representation, not ownership.

That is a very important distinction.

The third-party mandate: useful, but only while the situation is straightforward

Suppose your mum is perfectly capable of deciding what happens to her money but finds online banking frustrating. She might ask you to help pay bills, transfer money or manage regular payments. A third-party mandate can be a sensible solution.

MoneyHelper describes this type of arrangement as a way of giving a named person access to a bank or building society account and says it can be useful for day-to-day banking or while someone is waiting for a power of attorney to be set up.

It can therefore fill a very practical gap.

The problem is assuming that because it works today, it will automatically solve tomorrow’s problem. It won’t.

If your parent starts losing the ability to understand or make the relevant financial decisions, the third-party mandate is no longer the appropriate mechanism for managing their affairs. Government guidance makes this distinction explicitly.

This is where families can get caught out. They may have spent months helping a parent through a mandate, then discover that the parent’s circumstances have changed significantly. At that point, making an LPA may no longer be possible if the parent no longer has the mental capacity to make one.

That is why a mandate and an LPA should not necessarily be viewed as competing alternatives. For some families, the sensible approach is to use a mandate for immediate practical help while putting an LPA in place for the future.

Joint accounts solve a different problem

A joint account can look attractive because it is simple.

Two people can usually access the account. Bills can be paid without repeatedly asking the other account holder to transfer money. There’s no need to establish an attorney relationship just to carry out ordinary transactions.

But a joint account is not simply a cheaper version of an LPA.

The second person becomes a joint account holder. That can have consequences for how the money is viewed, how withdrawals are made and what happens if one account holder dies or loses capacity. The precise position depends on the account’s terms and the circumstances, so families should not assume that the bank will treat every joint account in exactly the same way.

The Office of the Public Guardian’s guidance notes that if one joint account holder loses mental capacity, a bank or building society can decide whether to restrict the account temporarily to essential transactions until a deputy is appointed or an appropriate power of attorney is registered.

That is worth understanding before relying on a joint account as your long-term incapacity plan.

There is another important question too: whose money is it?

If the account contains your parent’s savings, putting another person’s name on the account doesn’t automatically turn the arrangement into a simple substitute for an LPA. If the purpose is simply to allow a trusted person to help manage the parent’s money, an attorney arrangement can provide a much clearer legal framework.

It also makes the separation between the donor’s money and the attorney’s money explicit.

The trap families discover when capacity is lost. This is really the dividing line between the three options.

Imagine that your father is 82. You have helped him with his banking for several years. He has given you a third-party mandate, so you can make payments and deal with routine transactions. Then he has a stroke.

He is now unable to understand some of the financial decisions that need to be made. You might reasonably assume that because you have been helping him for years, nothing changes.

But the legal basis for helping him has changed. A third-party mandate is not designed to give someone authority to make decisions for a person who lacks mental capacity. An LPA, once properly made and registered, is specifically designed for this situation.

Without an LPA, the family may have to consider an application to the Court of Protection for a deputyship order. That is a very different process.

It means the family is no longer simply using an arrangement the parent chose in advance. The court is involved in deciding who should have authority and what that authority should cover.

This is one of the strongest arguments for making an LPA before it is needed.

Why the LPA is usually the better long-term answer

A Property and Financial Affairs LPA lets a person choose who they want to act for them.

That matters.

Your parent can decide whether that should be you, another family member, a friend or someone else they trust. They can also appoint more than one attorney and decide whether attorneys should act jointly, jointly and severally, or use a combination of the two.

They can also include appropriate preferences or instructions about how they want their affairs managed.

The LPA must be registered with the Office of the Public Guardian before an attorney can use it.

The current government guidance says registration normally takes around 8 to 10 weeks where there are no mistakes in the application, and the registration fee is £92 unless a reduction or exemption applies.

That waiting period is one reason families should not leave an LPA until a crisis is already developing. The document is most useful when it is already in place.

An LPA does not mean handing over control today

This is another misconception we regularly see in discussions about LPAs. Some people worry that making a Property and Financial Affairs LPA means their children can immediately take over their bank accounts.

It doesn’t necessarily work like that.

The donor decides when the attorneys can act. Government guidance explains that a Property and Financial Affairs LPA can be used while the donor still has capacity if the LPA allows it and the donor gives permission. Alternatively, the donor can choose for it to be used only if they lose capacity.

So an LPA can be thought of as putting the legal authority in place before it is needed. That’s particularly useful for families who want to avoid making a difficult legal decision during an already difficult period.

What an attorney can actually do

A Property and Financial Affairs attorney can potentially deal with a surprisingly wide range of financial matters.

This can include operating bank and building society accounts, paying bills, dealing with pensions and benefits, managing investments and dealing with property.

But the attorney is not becoming the owner of the donor’s money. They have legal responsibilities.

The donor’s finances should generally be kept separate from the attorney’s own finances, and the attorney must act in the donor’s best interests. Government guidance also makes clear that attorneys should keep appropriate records because their decisions can be scrutinised by the Office of the Public Guardian or the Court of Protection.

That’s another reason an LPA can be preferable to simply adding someone to an account. It creates a clearer framework around the relationship.

What happens at the bank after an LPA is registered?

Registering an LPA with the Office of the Public Guardian doesn’t necessarily mean the bank account is instantly changed.

The bank needs to establish that the attorney has authority.

Government guidance says banks may need to see the registered LPA, proof of identity and address, and potentially other information such as the relevant account number. The bank may also have its own process for setting up the attorney’s access.

This is worth doing before there is an emergency.

If your parent is still well, there is time to register the LPA, contact the bank and resolve any practical questions without a hospital bed, care home move or urgent bill hanging over the family.

It also gives the attorney an opportunity to understand how the bank wants them to operate the account. The right sequence for many families

For a parent who still has mental capacity but is beginning to need help, there is often a sensible sequence.

Start with the immediate problem. If they simply need help with everyday banking, ask the bank about a third-party mandate.

At the same time, think about the longer-term question. If the concern is what happens if your parent becomes unable to manage their finances, a Property and Financial Affairs LPA should be considered while they still have capacity. Once the LPA is made and registered, it can provide the longer-term authority.

This is not an either/or decision.

For some families, the practical answer is mandate now, LPA ready for later.

That gives the family something useful immediately without pretending that a third-party mandate solves the problem of future incapacity.

What we see when people prepare an LPA

One of the reasons we built Power of Attorney Online around guided completion and expert checks is that the difficult part is often not understanding the headline idea of an LPA. It is getting the details right.

Our published customer guidance uses the figure that 85% of LPA applications contain mistakes. That is one reason we put particular emphasis on checking the application before it is sent for registration.

The important point for families is that a mistake is not just an administrative nuisance. If an LPA is rejected or needs correcting, the delay can become particularly frustrating when the whole reason for making it was to have authority available when it is needed.

An LPA should therefore be treated as a piece of future planning, rather than something to complete only once a crisis has started.

A simple decision framework

The easiest way to think about the three arrangements is to start with the question: what problem are we actually trying to solve?

If your parent is mentally capable and simply wants help with everyday banking, a third-party mandate may be enough.

If two people genuinely need shared access to an account and understand the implications of having a joint account, that may be appropriate too.

If the real concern is future incapacity, an LPA is the important document.

And if your parent has already lost capacity and no LPA exists, a third-party mandate cannot simply be created to solve the problem. The family may need to consider deputyship or other appropriate arrangements.

Your situation	Most relevant option
Parent wants help paying everyday bills	Third-party mandate
Parent is travelling or wants temporary banking help	Third-party mandate or ordinary authority, depending on circumstances
Two people genuinely share an account	Joint account
Parent wants a trusted person to manage finances if they lose capacity	Property and Financial Affairs LPA
Parent has already lost capacity and there is no LPA	Court of Protection deputyship may be required
Parent needs help now and also wants future protection	Mandate now, LPA for the future

The important thing is not to confuse access to an account with legal authority to make decisions for someone who cannot make them themselves. Those are different things.

The cost question

Cost is often the reason families initially look at the simplest option.

A third-party mandate will generally be arranged through the bank rather than by creating a separate legal document such as an LPA.

A joint account does not involve creating an LPA either, although the bank’s own account terms and circumstances will determine what happens.

An LPA has a registration fee. The current government fee is £92 per LPA, unless the donor qualifies for a reduction or exemption.

With Power of Attorney Online, our current service price is £125 for a single LPA or £250 for a pair, plus the applicable Office of the Public Guardian registration fees.

That means the financial comparison should not simply be “what is cheapest today?”

It is worth asking what each option is actually buying you.

A third-party mandate may solve today’s banking problem. A joint account may provide shared access. An LPA provides a formal route for someone chosen by the donor to manage their property and financial affairs if they later cannot do so themselves.

Those are very different outcomes.

What about pensions, investments and other financial providers?

The same principle applies beyond the current account.

A Property and Financial Affairs attorney can potentially deal with pensions, benefits, investments and property, although each organisation will have its own procedures for verifying authority.

A third-party mandate is much narrower. It’s primarily a banking arrangement.

That distinction becomes important when a parent’s finances are spread across several places. They may have a current account, savings account, investment portfolio, private pension and property.

Getting access to one bank account doesn’t automatically give you authority over everything else.

An LPA is much closer to the whole-picture solution because it concerns the donor’s property and financial affairs rather than one particular bank account.

Don’t make a joint account just because it seems easier

There is a natural temptation here.

If your mum says, “Why don’t I just put you on my account? Then you can sort everything out.”

It sounds wonderfully simple. But before doing that, stop and ask why.

If the purpose is simply to make it easier for you to pay her bills, a third-party mandate may be more appropriate. If the purpose is to make sure you can manage her finances if she becomes unable to do so, an LPA is worth considering. If the purpose is genuinely to make the account jointly owned and operated, then a joint account may make sense.

The legal and financial consequences are different.

In particular, families should be cautious about using joint accounts as a substitute for proper estate or incapacity planning without understanding the consequences.

The conversation to have with your parent

This does not need to start with, “You need a power of attorney.”

That can sound alarming. A better conversation is often much more ordinary.

“Would it help if I could deal with the bills if you were away?”

“Who would you want to help with your finances if you were ill?”

“If you were in hospital and couldn’t access your banking, who would you want the bank to speak to?”

“Would you want me to be able to deal with things if you couldn’t make the decisions yourself?”

Those questions get to the underlying issue.

The LPA is simply the legal mechanism that allows your parent to put their wishes into effect. And importantly, it is their choice.

They choose the attorney.

They choose whether to make a Property and Financial Affairs LPA.

They can decide whether attorneys act separately or together.

That element of choice is something a family should not underestimate.

FAQs

Is a third-party mandate the same as a power of attorney?

No. A third-party mandate is an arrangement with a bank or building society allowing someone else to operate an account. A Property and Financial Affairs LPA is a legal document that appoints an attorney to make decisions about the donor’s property and finances.

Can a third-party mandate continue after someone loses mental capacity?

It should not be relied upon as a solution to loss of mental capacity. Government guidance specifically says a third-party mandate is not appropriate when the account holder is losing the ability to make the relevant decisions.

Is a joint bank account better than an LPA?

Not necessarily. They serve different purposes. A joint account gives both account holders access to the account, whereas an LPA gives a chosen attorney authority to act for the donor. If the main concern is future incapacity, an LPA is generally the more appropriate planning tool.

Can I use an LPA while my parent still has capacity?

A Property and Financial Affairs LPA can be used while the donor still has capacity if the LPA allows it and the donor gives permission. Alternatively, the donor can specify that attorneys should only act once they have lost capacity.

Does an LPA give me ownership of my parent’s money?

No. An attorney acts on behalf of the donor. They must act in the donor’s best interests and should keep the donor’s finances separate from their own.

What happens if my parent loses capacity without an LPA?

A third-party mandate may no longer be appropriate, and the family may need to apply to the Court of Protection for a deputyship order. The court can decide who should manage the person’s affairs when they have not made, or are no longer capable of making, a power of attorney.

Can my parent make an LPA online?

Yes. LPAs can be made online or using paper forms. They still need to be properly signed, witnessed and registered with the Office of the Public Guardian before an attorney can use the LPA.

The important decision is not really about banking For many families, the question starts with a bank account.

“Can I help Mum with her banking?”

But that is often not the question they are ultimately trying to answer. The bigger question is what happens if Mum can no longer manage her own affairs.

A third-party mandate can be a useful answer to the first problem. A joint account can be appropriate in the right circumstances. But neither should automatically be treated as a substitute for an LPA.

A Property and Financial Affairs LPA lets your parent make the important decision while they can still make it: who do I trust to look after my affairs if I cannot?

That is the part that can’t easily be fixed afterwards.

If your parent still has mental capacity, there is usually no need to wait for a crisis before having that conversation. The practical banking arrangement can be dealt with today, while the longer-term legal authority can be put in place for tomorrow.

For families, that is often the safest way to think about the choice: solve the banking problem you have now, but do not mistake it for a plan for the future.