If you die and your ex — your child's other parent — has parental responsibility, then in almost every case the children will go to live with them. A will cannot change that. You can name a guardian, you can write down in detail why you do not want your former partner raising your children, and none of it moves the children away from a surviving parent who holds parental responsibility. This is one of the hardest answers on this site, and softening it would not help you.

So if you are separated, do not trust your ex, and have been searching for the clause that keeps the children away from them if you die, the honest position is that there almost certainly is not one. Custody — the day-to-day care of your children — is not something you can hand to someone else in a will while their other parent is alive and has parental responsibility for them.

But there is something you can control, and it is the thing that protects your children in practice: the money. You can make sure that whatever you leave reaches your children rather than being absorbed into your ex's household budget, and you can build it so that it holds up even when the person spending it is someone you would never have chosen. That is where the rest of this page goes.

At a glance

  • If your ex has parental responsibility, your children normally go to them when you die. A will cannot override that.
  • A guardian you appoint only takes effect once no parent with parental responsibility survives.
  • Genuine safeguarding concerns are dealt with by the family court in your lifetime, not by a clause in your will.
  • What you can control is the money: leave it in trust, not outright, and not to your ex.
  • Point life cover and pension nominations at the trust, so the money is spent on the children and recorded.

The short answer: parental responsibility decides, not your will

The concept that governs all of this is parental responsibility — the bundle of rights and duties a parent has for a child. It is the thing a court looks to when deciding who cares for a child, and a will cannot take it away from someone who has it.

A guardian appointed in a will is real and it matters, but it is designed to fill a vacuum, not to win a contest. Under the Children Act 1989, a guardian you name takes over only when there is no surviving parent with parental responsibility. If the other parent is alive and holds it, your appointment simply waits in the background and never takes effect while they are there. That is the whole answer to the question most separated parents are really asking, and everything else on this page follows from it.

It feels wrong, because you are the one who has done the day-to-day raising and you know things about your ex that a stranger would not. But the law starts from the position that a child's own surviving parent is the default carer, and it takes a great deal to move off that position.

Who actually has parental responsibility

Because everything turns on parental responsibility, it is worth checking who genuinely holds it, because it is not automatic for everyone.

A mother has parental responsibility automatically from birth. A father has it if he was married to the mother when the child was born, or — for births registered from 1 December 2003 in England and Wales — if he is named on the birth certificate. He can also acquire it by a formal parental responsibility agreement with the mother or by a court order. A second female parent or a civil partner can hold it on a similar basis. The point that matters for you is this: a father who was never married to the mother and is not on the birth certificate may not have parental responsibility at all, and if he does not, your guardian appointment is not blocked by him in the way it would otherwise be.

So the first practical step is unglamorous. Check the birth certificate and check whether any court order or agreement is in place. The answer decides whether a guardian appointment can ever take effect, and people are sometimes wrong about their own situation.

When a guardian you named does take over

There are two situations where a guardian you appoint does step in. The obvious one is where no parent with parental responsibility survives — if both parents die, or if the surviving parent never had it. The guardian then takes over the child's care, and naming one is what shortens the gap and keeps the decision in your hands rather than a court's.

There is also a narrower exception: where a court order said the child was to live with you, and not also with the other parent, your appointment of a guardian can take effect on your death even though the other parent is still alive. That is a specific situation with specific wording, and it does not apply to an ordinary arrangement or a contact order. If you think it might apply to you, it is worth getting the order checked rather than assuming.

Whatever your circumstances, name a guardian anyway. It costs nothing and it covers the case where the other parent is not there to step in. And be clear about who counts: a godparent, for instance, has no legal standing at all unless they are also appointed, a point we set out in why godparents are not legal guardians.

If you have genuine safeguarding concerns

If your worry is not preference but genuine risk — a parent with a history that would put the children in danger — then the route is not a will. It is the family court, and it is best used while you are alive.

During your lifetime you can ask the court for orders that shape or limit the other parent's involvement, and evidence built up then carries far more weight than a note discovered after your death. After you die, a relative who is worried can apply for a child arrangements order or, in more serious cases, for special guardianship, but they are starting a contest, not enforcing your wishes. The court will apply the welfare checklist in the Children Act 1989 — the child's needs, the effect of any change, any risk of harm, and how capable each adult is — and it decides on the child's welfare, not on your instructions.

A letter setting out your reasons is still worth writing. It will not bind anyone, but it gives a judge context and gives a worried relative something concrete to point to. Treat it as evidence you are leaving behind, not as a decision you are making for the court.

The one thing you can control: the money

Here is where a separated parent has real power. You cannot usually choose the carer, but you can choose exactly where your money goes and how it is looked after — and getting that right is what actually changes your children's lives.

Two mistakes do the damage. The first is leaving money to your ex in the expectation that they will spend it on the children; there is nothing to make them, and money handed to an adult becomes that adult's money. The second is leaving it outright to a young child, which the law will not allow to happen directly anyway. There is a further, quieter risk in trusting an adult to pass money on later: their own will can be rewritten at any time, and what they promised you can quietly disappear — the problem we describe in how an adult you leave money to can later rewrite their own will.

The answer to all of this is a trust. You leave the children's inheritance to trustees you choose, to be used for the children, rather than to any adult to spend as they see fit. Done properly, the money is ring-fenced, spent on the children, and recorded — whoever the children end up living with.

Building it so it holds: trusts, trustees and where the cover points

The structure is straightforward once you see it laid out. Leave the children's share in a trust set up in your will. Appoint at least two trustees you trust — and, plainly, not your ex — to hold and manage the money and to decide what is spent on the children. Keeping the person who controls the money separate from the person raising the children is sensible in any family, and we weigh it up in keeping the person who raises the children separate from the person who controls the money.

Then point your other money at the same place. Life cover can be written in trust for the children rather than paid to your estate or to a named adult, which keeps it out of your ex's hands and away from any claim on your estate. A pension death-benefit nomination can be directed to the children or the trust rather than to a former partner, though the scheme usually keeps a final discretion, so the nomination is guidance, not a guarantee. Some parents prefer cover that pays a regular income across the years of childhood — family income benefit — rather than a single lump sum an adult would control; a broker can explain how that works. If you want to set cover up so it points at a trust for the children, you can get life insurance quotes and have an FCA-authorised broker arrange it that way.

One more warning worth heeding: a former spouse who has not remarried can sometimes make a claim against your estate, which can pull money away from the children — the risk we set out in a former spouse's own claim against your estate. And where a child has lifelong needs rather than simply being young, the planning is different again, and cover has to be built to outlast you, which we cover in cover designed to outlive you where a child has lifelong needs.

Scotland and Northern Ireland

The shape of the answer is the same across the UK, though the labels differ. In Scotland the concept is "parental responsibilities and parental rights" under the Children (Scotland) Act 1995, and a surviving parent who holds them normally continues to care for the child, just as in England and Wales. Northern Ireland works to the Children (Northern Ireland) Order 1995, again broadly similar. In every part of the UK a will cannot move a child away from a surviving parent who holds responsibility for them.

The money planning travels across borders too — a trust for the children, careful choice of trustees, and cover pointed at the trust rather than at an individual — although the detail of how a trust is set up and how an estate is administered differs, particularly in Scotland. If you are also untangling what happens to a home and an estate when a parent dies without a will, our guide to what happens to a house when a parent dies without a will sits alongside this one, and you can read the wider cluster in our guide to wills, guardianship and children. For a fuller treatment of the custody question itself, see our fuller guide to whether an ex automatically gets the children.

Frequently asked questions

If I die, does my ex automatically get the children?

Where your ex holds parental responsibility, they normally continue caring for the children, and any guardian you appointed does not take effect. A will cannot move care of a child away from a surviving parent who already holds parental responsibility, so in most separated families the children will go to their other parent.

Can I stop my ex getting the children in my will?

A will cannot override a surviving parent's parental responsibility. Where there are genuine safeguarding concerns, the route is the family court during your lifetime, not a clause in a will. Another relative could apply to the court after your death, but they would have to prove their case against the welfare checklist rather than simply enforce your wishes.

What can I do to protect my children financially?

Leave their share in trust rather than outright, choose trustees you trust rather than your ex, and point your life cover and pension nominations at that trust rather than at an individual. Money is then spent on the children and recorded, whoever they end up living with, instead of becoming another adult's to use as they wish.