Wills | May 22, 2026 — 11 Minute Read

What Is Sideways Disinheritance?

Quick answer

Sideways disinheritance happens when assets pass to a spouse, civil partner or partner, but later fail to pass to the children or beneficiaries originally intended.

This can happen if your surviving partner changes their Will, remarries, owns the family home outright, or leaves assets to different people. It is a common concern in second marriages, blended families and situations where one or both partners have children from a previous relationship.

A carefully drafted Will, suitable property ownership and trust planning, such as a Flexible Life Interest Trust, can help reduce this risk.

What is sideways disinheritance?

Sideways disinheritance happens when someone’s estate passes sideways to a partner, spouse or civil partner, but does not then pass down to the children or beneficiaries they originally wanted to protect.

For example, you may leave everything to your spouse or partner, trusting that they will later pass what remains to your children. However, once they inherit those assets outright, they may be free to make their own decisions about what happens next.

They may later remarry, make a new Will, fall out with family members, need care, face financial difficulties, or decide to leave their estate to different people.

In many cases, sideways disinheritance is not caused by anyone deliberately doing something wrong. It often happens because life changes after the first person dies, and the original estate plan did not include enough protection.

That is why careful estate planning is so important. A well-structured Will can help protect your partner during their lifetime while giving you greater control over who may benefit from your estate in the future.

Why is sideways disinheritance a concern?

Sideways disinheritance can be distressing because it often goes against what the first person wanted to happen.

It can mean that children from a previous relationship receive less than expected, or nothing at all. It can also create tension between a surviving partner, stepchildren, adult children and new family members.

This is especially important where:

You have children from a previous relationship
You are in a second marriage
You and your partner have different beneficiaries in mind
You own a home together
You want your partner to be looked after, but your children to inherit later
You are worried about what could happen if your partner remarries
You are relying on Mirror Wills
You want to protect family wealth for future generations

Even where everyone gets along now, it is still important to make your wishes legally clear. Verbal promises and informal family agreements are rarely enough to protect your estate.

How can sideways disinheritance happen?

Sideways disinheritance can happen in several ways. Some of the most common scenarios include:

Your partner changes their Will after your death
Your partner remarries after your death
Your share of the home passes fully to your partner
Your partner later leaves assets to their own children, a new spouse or other beneficiaries
Your estate is affected by care fees, debt or family disputes
Your Will does not clearly protect children from a previous relationship
You die without a valid Will in place

For example, you may have a simple Will that leaves everything to your spouse. This may feel straightforward, but once your spouse inherits your estate, those assets usually become theirs. Unless your Will includes suitable planning, you may have little control over who receives those assets after your spouse dies.

This can be a particular concern in blended families, where both partners may want to provide for each other while also protecting children from previous relationships.

If you are part of a blended family, it is especially important to make sure your Will reflects both your current wishes and the people you ultimately want to benefit.

Find out more about estate planning for blended families.

Example of sideways disinheritance

David and Sarah are married. David has two children from a previous relationship. Sarah has no children of her own.

David and Sarah make simple Mirror Wills, leaving everything to each other, and then to David’s children after they have both died.

David dies first, so everything passes to Sarah. A few years later, Sarah remarries and makes a new Will leaving her estate to her new husband. When Sarah dies, David’s children may receive nothing from the assets David originally left behind.

This is sideways disinheritance.

If David had used a suitable trust in his Will, Sarah could still have been protected during her lifetime. David could have had more control over how his share of the estate was used during Sarah’s lifetime and who could benefit from it later.

Can my partner change their Will after I die?

In many cases, yes. If your partner has their own Will, they can usually change it at any time, provided they have the mental capacity to do so and are not being put under undue pressure.

This is one of the main risks with standard Mirror Wills. Mirror Wills are often used by couples who want to leave everything to each other and then to the same beneficiaries after they have both died. However, Mirror Wills are not usually legally binding on the surviving partner.

This means your partner could change their Will after your death. They may choose different beneficiaries, reduce someone’s inheritance, exclude a child, or leave their estate to a new spouse or partner.

Mirror Wills can still be useful in some circumstances, but they may not offer enough protection if you are worried about sideways disinheritance.

If you are relying on Mirror Wills, it is worth reading our guide to what a Mirror Will is and whether it is right for you.

What happens if my partner remarries after I die?

Remarriage is one of the situations that can increase the risk of sideways disinheritance.

In England and Wales, getting married generally revokes an existing Will, unless the Will was made in contemplation of that specific marriage. This means that if your surviving partner remarries and does not make a new valid Will, their estate may be distributed in a way neither of you originally intended.

This could mean assets you wanted to pass to your children are redirected to your partner’s new spouse, or shared in a way you would not have chosen.

For example, you may leave everything to your spouse, expecting them to pass what remains to your children when they die. If they later remarry, their new spouse may become entitled to part or all of their estate, depending on the circumstances and whether a valid Will is in place.

With the right estate planning, you may be able to provide for your partner while still setting out how your share of the estate should be dealt with in the future.

What happens to my share of the house?

For many families, the family home is the most valuable asset. How the property is owned can have a major impact on whether your share can be protected.

If you own your home as joint tenants, your share will usually pass automatically to the surviving owner when you die. This happens outside the terms of your Will. While this can be simple, it may not protect your share of the home for your children or other beneficiaries.

If you own your home as tenants in common, each person owns a defined share of the property. This means your share can be left in your Will, including into a trust.

This can be useful if you want your partner to continue living in the home after your death, while also making sure your share is ultimately dealt with in line with your wishes.

Read more about severance of tenancy and the difference between joint tenants and tenants in common, or watch our video on joint home ownership and estate planning.

Can I protect my children’s inheritance and still look after my partner?

Yes, in many cases it is possible to do both.

This is often the key estate planning challenge for couples in second marriages or blended families. You may want your spouse or partner to be financially secure after your death, but you may also want to make sure your children inherit your share of the estate later.

Leaving everything outright to your partner may feel simple, but it can leave your children’s inheritance exposed. Leaving everything directly to your children may not provide enough security for your partner.

A trust-based Will can help balance these priorities. One option may be a Flexible Life Interest Trust.

How can a Flexible Life Interest Trust help?

A Flexible Life Interest Trust, often called a FLIT, is a type of trust that can be written into your Will. It may help reduce the risk of sideways disinheritance by allowing your surviving partner to benefit from assets during their lifetime, while giving greater control over who should ultimately benefit from those assets later.

Instead of leaving assets directly to your partner, those assets are placed into a trust when you die. Your partner can then usually benefit from them through income, and sometimes through access to capital if the trust allows it.

A key feature of a Flexible Life Interest Trust is what happens after the life tenant dies. Rather than the trust simply ending and the capital passing automatically to fixed beneficiaries, it will usually continue as a discretionary trust. This means the trustees can decide who should benefit, when they should benefit, and to what extent.

This flexibility can be useful where you want your partner to be looked after, but do not want your estate to pass outright to them with no further control. It can be particularly relevant in blended families, second marriages and situations where you have children from a previous relationship.

A FLIT is not suitable for everyone. The wording of the trust, the choice of trustees and your wider family circumstances all need to be considered carefully.

For more information, read our full guide to Flexible Life Interest Trusts.

Could a property trust help protect my share of the home?

In some cases, property trust planning may also help protect a share of the home for chosen beneficiaries.

This may be relevant where you want your surviving partner to continue living in the property, but you also want your share of the home to be dealt with in line with your wishes later.

Property trust planning should be considered carefully, as the right approach will depend on how the property is owned, your family circumstances and your wider estate planning goals.

Find out more about how property trust planning works.

Is sideways disinheritance only a risk for blended families?

No. Sideways disinheritance is often associated with blended families, but it can affect many different family situations.

It may be a concern if:

You have children from a previous relationship
You and your partner have different beneficiaries in mind
You are not married but own property together
You have stepchildren you want to provide for
You are worried about your partner remarrying after your death
You want to protect family wealth for future generations
You want to avoid disputes between children and a surviving partner

It can also be a concern for couples who assume that a simple Will, Mirror Will or verbal agreement will be enough to make sure their wishes are followed.

What if I die without a Will?

If you die without a valid Will, your estate will be distributed under the intestacy rules. These rules decide who inherits, regardless of what you may have wanted.

This can be particularly problematic for unmarried couples, blended families and families where there are children from previous relationships.

Unmarried partners do not automatically inherit under the intestacy rules, no matter how long you have been together. Stepchildren also do not automatically inherit unless they have been legally adopted.

A valid Will allows you to make your wishes clear and decide who should inherit from your estate. It can also include trust provisions to help protect your chosen beneficiaries.

How can you protect your family from sideways disinheritance?

There are several estate planning steps that may help reduce the risk of sideways disinheritance.

1. Make a professionally drafted Will

A Will allows you to decide who should inherit from your estate. It can also include trust provisions to protect assets for specific beneficiaries.

2. Review how your property is owned

If you own property jointly, it is important to understand whether you own it as joint tenants or tenants in common. This affects whether your share passes automatically to the other owner or can be controlled by your Will.

3. Consider whether a trust is appropriate

A trust-based Will can help balance the needs of a surviving partner with the interests of children or other beneficiaries.

Depending on your circumstances, this may include a Flexible Life Interest Trust or another form of trust planning. The right option will depend on your family, your assets and your wishes.

4. Keep your Will up to date

Marriage, divorce, remarriage, new relationships, births, deaths and property purchases can all affect your estate planning needs.

It is sensible to review your Will regularly, especially after major life changes.

5. Get advice before relying on Mirror Wills

Mirror Wills can work well for some couples, but they do not usually stop the surviving partner from changing their Will later.

If you want greater certainty over what happens after both partners have died, you may need a more protective structure.

6. Talk openly with your family where appropriate

Estate planning can be sensitive, but clear communication may help reduce confusion and disputes later. This does not replace a legally valid Will, but it can help your loved ones understand your wishes.

How ELM Legal Services can help

At ELM Legal Services, we help clients across England and Wales make clear, carefully considered plans for the future.

We can help you understand whether your current Will offers enough protection, how your property ownership affects your estate, and whether trust planning may be suitable for your circumstances.

Our team can talk you through your options in plain English, so you can make informed decisions about how best to protect the people you care about.

FAQs

Is sideways disinheritance intentional?

Not always. Sideways disinheritance often happens because circumstances change after someone dies, rather than because the surviving partner deliberately ignored their wishes. A new relationship, remarriage, family disagreement, financial pressure or an outdated Will can all change where assets eventually end up.

Who is most at risk of sideways disinheritance?

People in second marriages, blended families, unmarried relationships and families with children from previous relationships are often more at risk. It can also affect homeowners who own property jointly and couples who assume that Mirror Wills or verbal promises will be enough to protect their wishes.

Can a verbal promise protect my children’s inheritance?

A verbal promise is unlikely to offer reliable protection on its own. Even if your partner genuinely intends to follow your wishes, their circumstances may change after your death. It is much safer to put your wishes into a professionally drafted Will and take advice on whether trust planning is appropriate.

Should I update my Will if I enter a new relationship?

Yes, it is sensible to review your Will when you enter a new relationship, remarry, separate, divorce, buy property or have children. These life changes can affect who may inherit and whether your existing Will still reflects your wishes.

How do I know if my current Will protects my children?

The best way to check is to have your Will reviewed by an experienced estate planning professional. They can look at how your assets are owned, who your Will benefits, and whether trust planning may be appropriate for your circumstances.

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