Estate Planning for Blended Families: Protecting All Your Children's Inheritance When You Remarry or Cohabit

Introduction

Few conversations are more emotionally charged—and legally complex—than planning what happens to your assets when you die. But if you're in a second marriage, civil partnership, or cohabiting relationship, this conversation becomes inescapably urgent. The core tension is stark: the planning that protects your current partner directly conflicts with protecting your children from a previous relationship.

Without careful, deliberate planning, you face an impossible choice. The law will make it for you—and the result will almost certainly disappoint someone you love.

This guide exists because standard wills, and the default rules of intestacy, are profoundly inadequate for blended families. They were written for simpler households. If you remarry without updating your will, the legal system will likely transfer your estate to your new spouse—and from there, your children may receive nothing at all.

The good news: with proper planning using life interest trusts, discretionary trusts, and carefully considered wording, you can protect both your current partner and your children. It requires honesty, legal clarity, and decisions made now—but it is entirely possible.

The Default Problem: Intestacy Rules and Simple Wills

What Happens Without a Will (Intestacy)

If you die without a valid will, the rules of intestacy determine who inherits your estate. For England and Wales, the rules are deceptively simple—and devastating for blended families:

• If you leave a surviving spouse or civil partner and children: The spouse receives the first £322,000 of the estate, all personal possessions, and half of the remaining assets. The other half is divided equally among your children [1].
• If you leave only a surviving spouse and no children: The spouse inherits the entire estate.
• Crucially: Unmarried partners inherit nothing. Not a penny. A cohabiting partner of 20 years has no automatic legal entitlement [5].
• Stepchildren are not recognised. Children from a previous relationship who were not legally adopted do not inherit under intestacy rules, even if they were financially dependent and treated as part of your family.

For many blended family households, this is where the problem begins.

The "Simple Will" Problem

You may already have a will from your first marriage. Many people do. But in England and Wales, marriage automatically revokes any will made before that marriage, unless the will was explicitly drafted in contemplation of that specific marriage [2].

This means: if you remarried without redrafting your will, your old will is legally void. You are now effectively dying intestate—and the intestacy rules will apply.

Even if you made a new will after your current marriage, a standard "everything to my spouse" will creates a cascade of problems:

Scenario: David (60) remarries Sarah (52). David has two adult children from his first marriage.

David makes a straightforward will leaving everything to Sarah. On David's death, Sarah inherits his entire £800,000 estate. The children receive nothing immediately.

Sarah is now 52, with an 800,000-pound estate. If Sarah remarries within five years—which is common—David's original children will compete with Sarah's new partner for those assets. If Sarah has her own children, they inherit from her, not from David. Even if Sarah intends to leave money to David's children in her will, Sarah could be legally challenged by her own family. Or Sarah could simply change her mind.

Result: David's children receive nothing.

This is not a rare problem. It is the default outcome.

Life Interest Trusts (Immediate Post-Death Interest Trusts)

How They Work

A life interest trust (formally called an Immediate Post-Death Interest, or IPDI trust) operates as follows:

1. On your death, the trust is created under your will.
2. Your surviving spouse or civil partner becomes the "life tenant." They receive all income from the trust assets for their lifetime and may have the right to live in the property.
3. Your children (or other named beneficiaries) are the "remainders beneficiaries." When the surviving spouse dies, the capital passes to them.
4. The surviving spouse cannot touch the capital. They cannot withdraw lump sums, spend it down, or redirect it to a new partner or their own children (unless your will explicitly permits this).

Continuing David's scenario:

David establishes a life interest trust leaving £600,000 of his estate to a trust. Sarah receives the income from that £600,000 for life (perhaps £18,000 per year) and the right to live in the house. David's £200,000 passes to his children immediately. On Sarah's death, the £600,000 trust capital passes to David's children.

Result: David's children inherit £600,000 plus the immediate £200,000. Sarah is financially secure for life.

IHT Treatment: The Critical Detail

When you transfer assets into a life interest trust on your death, those assets qualify for the spouse/civil partner exemption [3]. This means they pass to the trust at nil IHT.

However—and this is crucial—when the surviving spouse dies, the underlying assets are included in their estate at their full value. At that point, if the surviving spouse's total estate (including the life interest trust property) exceeds the nil-rate band, IHT becomes due on the second death.

Example: David's £600,000 trust, now passed to Sarah with a life interest. When Sarah dies 15 years later, it is included in Sarah's estate for IHT. If Sarah's own assets plus the trust assets total £325,000 (above the current nil-rate band), 40% tax is due on the excess.

This is acceptable for many families—the priority is protecting the children's inheritance, and some IHT is an acceptable cost. But it is not a complete solution. For larger estates or where you want to minimize IHT on the second death, additional planning is needed.

When Life Interest Trusts Are Appropriate

Life interest trusts work well when:

• You want to provide genuine security and income for your surviving spouse for their lifetime
• You can trust that your spouse will not be unduly influenced to spend or redirect assets
• Your spouse has their own modest assets and does not need access to capital
• Your children are adults and in a stable financial position
• You want simplicity: the trust operates automatically once established

They do not work well when:

• Your spouse is significantly younger and may need capital flexibility over decades
• Your spouse has serious debts or faces potential claims from creditors
• You genuinely cannot trust your spouse to respect the boundaries of a life interest (though this is rare)
• Your estate is very large and minimizing second-death IHT is a priority

Combining Life Interest Trusts with Discretionary Trusts

To address the IHT issue on the second death and provide more flexibility, many advisers recommend a two-tier structure:

1. A life interest trust for the surviving spouse (as above)
2. A discretionary trust funded with your nil-rate band (currently £325,000 per person)

On your death, your nil-rate band is allocated to a discretionary trust, which benefits your spouse, children, and potentially grandchildren. The trustee has absolute discretion over who receives what and when. This trust is not included in the surviving spouse's estate when they die—a significant IHT advantage.

Revised scenario:

David's estate: £800,000. His nil-rate band is £325,000.

• Life interest trust: £475,000. Sarah receives income and security; David's children inherit capital on Sarah's death.
• Discretionary trust: £325,000 (David's nil-rate band). Trustees can use this to pay living expenses for Sarah or make distributions to David's children. On Sarah's death, the £325,000 does not form part of her taxable estate.

This achieves two goals: Sarah is secure, David's children inherit capital, and the second-death IHT liability is substantially reduced.

Cohabiting Partners and Blended Families

The Inheritance Gap

If you are not married and not in a civil partnership, your partner has no automatic inheritance rights whatsoever [5]. This is true regardless of how long you have lived together, whether you have shared children, or whether you have built a joint life.

Under the intestacy rules, a cohabiting partner of 30 years receives nothing. The estate passes to your children, parents, or more distant relatives—but not to your partner.

Additionally, unmarried partners cannot use the spouse/civil partner IHT exemption. Any assets you leave to them are subject to 40% inheritance tax above your nil-rate band. Married partners and civil partners are exempt from IHT entirely, up to unlimited value [5].

Protecting a Cohabiting Partner

If you want to provide for a cohabiting partner, you must:

1. Make an explicit will naming them as a beneficiary
2. Consider whether a life interest trust is appropriate, using the same principles as outlined above
3. Use discretionary trusts if you want to provide flexibility and protect the inheritance for your children
4. Ensure your partner is provided for by explicit bequest—otherwise the intestacy rules will bypass them entirely

A common structure for cohabiting couples with blended families:

• Outright cash bequest to the cohabiting partner (e.g., £100,000 for immediate security)
• Life interest in the house (the partner can live there for life; on their death it passes to your children)
• Discretionary trust funded with a portion of your nil-rate band, allowing trustees flexibility to support your partner or your children

Claims Under the Inheritance (Provision for Family and Dependants) Act 1975

Even without a will, a cohabiting partner who was financially dependent on the deceased may be able to make a claim under the Inheritance Act 1975 [4]. This is not an automatic right—it requires proving dependency and making an application to court—but it provides some protection if planning was neglected.

Stepchildren can also claim under this Act if they were treated as children of the deceased and were financially dependent. However, these claims are uncertain, contested, and expensive. They are not a substitute for proper planning.

Marriage, Divorce, and the Revocation of Wills

Marriage Revokes Your Will

This cannot be overstated: in England and Wales, marriage (or entry into a civil partnership) automatically revokes any existing will, unless that will was made in contemplation of that marriage [2].

If you remarried without updating your will, your previous will is void. Your estate will pass under the intestacy rules—which means your current spouse inherits significant assets, and your children from a previous relationship may receive less or nothing at all.

The exception is narrow: your will must have been drafted before the marriage with specific language stating that it was made in contemplation of marriage to a specifically named person.

Urgent Action Required

If you are in a new marriage or partnership and do not have a current will:

1. Make an appointment with a solicitor immediately. This is not something to delay.
2. Review any previous will to confirm it has been revoked.
3. Draft a new will that reflects your current wishes and includes protective mechanisms for your children.

This is particularly urgent if:

• You are in a new marriage and have significant assets
• You have children from a previous relationship
• You have a blended household with step-children
• Your previous will left everything to an ex-partner (because that will is now void, and the intestacy rules apply)

Divorce and Wills

Divorce does not revoke a will (as remarriage does). However, on divorce, your ex-spouse is automatically treated as if they predeceased you. Any gifts to them in your will lapse, and they cannot act as an executor or trustee [2].

This is actually helpful, but it means you should still update your will after divorce to clarify your intentions and remove any ambiguity.

Mutual Wills and Why They Are Often Inappropriate for Blended Families

A "mutual will" is an agreement between two people (often a couple) that they will each make wills with matching provisions, and that the surviving spouse will not change their will after the first spouse dies. This can be legally binding.

Mutual wills might seem attractive: they guarantee that David's children will inherit if David predeceases Sarah, because Sarah has promised not to change her will.

But mutual wills are dangerous for blended families:

1. The surviving spouse loses flexibility. If Sarah's circumstances change dramatically—she faces unexpected care costs, needs to help her own children, remarries—she may be unable to change her will without breaching the mutual will agreement and exposing herself to claims from David's children.

2. Life changes make mutual wills impossible to sustain. A serious illness, a new relationship, financial crisis, or family estrangement may make the original provisions unworkable.

3. Modern estates are complex. Business interests, investment properties, pension arrangements, and international assets may require flexibility that a mutual will cannot provide.

For blended families, life interest trusts and discretionary trusts are far superior because they provide automatic legal protection without requiring the surviving spouse to agree to be locked into arrangements they cannot change.

Keeping Assets Separate: The Limits

Many people in blended families ask: "Can I keep my money separate and protect it for my children?"

The answer is nuanced:

What Can Be Separated

• Bank accounts and investments in your sole name can be protected through your will and trusts. They form part of your estate and can be directed to your children.
• Property owned as tenants in common (rather than joint tenants) can be left to your children. Your share does not automatically pass to your cohabiting partner. This is critical for blended families and should be the default for cohabiting couples and remarried couples.
• Pension assets can often be protected through your beneficiary designation. Pensions do not form part of your estate under the intestacy rules; they pass directly to whoever you name as beneficiary.
• Life insurance proceeds pass to your named beneficiary, bypassing your estate.

What Cannot Be Separated

• Jointly owned property (held as joint tenants) automatically passes to the other owner on your death, regardless of your will. This is powerful for married couples wanting to provide for a spouse, but problematic if you own property with a cohabiting partner and want to protect it for your children.
• Joint bank accounts typically pass to the surviving account holder.
• Life insurance policy owned jointly may create complications.

The Critical Point

Simply "keeping money separate" is not a substitute for a proper will and trust structure. Your assets must have a destination, and that destination must be clarified in a valid, recent will. Without that document, the intestacy rules apply—and they ignore your intentions.

Pre-Nuptial and Post-Nuptial Agreements

Pre-nuptial and post-nuptial agreements are not strictly estate planning tools, but they are relevant to blended families because they can clarify what happens to assets if your marriage breaks down.

A pre-nuptial agreement (made before marriage) or post-nuptial agreement (made during marriage) can specify:

• Which assets you brought into the marriage and intend to keep separate
• How assets acquired during the marriage will be divided
• What provision each party will make for children from previous relationships

These agreements are not automatically binding in England and Wales, but courts increasingly treat them as significant evidence of the parties' intentions. They can be particularly valuable in blended families where both partners want to ring-fence assets for their respective children.

However, pre-nuptial and post-nuptial agreements do not replace wills and trusts. They deal with family law (property division on divorce), not inheritance. You still need a proper estate plan.

A Worked Example: David and Sarah

The Setup:

David (60) has accumulated £800,000: a house worth £500,000 (mortgaged), savings of £200,000, and pension assets worth £100,000. He has two adult children from his first marriage. He has remarried Sarah (52), who has modest assets (£50,000) and two adult children from her previous relationship.

David wants to:

1. Ensure Sarah is financially secure and can remain in the house after his death
2. Ensure his own children inherit a significant portion of his estate
3. Minimize IHT

The Plan:

David's solicitor recommends:

1. Property held as tenants in common. David clarifies that his 50% share of the house will not automatically pass to Sarah. Instead, it will form part of his estate.

2. A life interest trust for the house. David's will directs that Sarah receives the right to live in the house for life and to receive a portion of rental income if the house is rented. On Sarah's death, the house passes to David's children.

3. A discretionary trust funded with £325,000 (David's nil-rate band). The trustees—David's eldest child and a professional trustee—can use this to support Sarah, pay care costs, or distribute to David's children. This avoids second-death IHT.

4. Outright bequests. £75,000 to Sarah (for immediate security and flexibility), £100,000 divided equally between David's children (immediate inheritance), and his pension (£100,000) directed directly to his children via the beneficiary designation form (bypassing his estate).

5. A will in contemplation of marriage. David explicitly states in his will that it is made in contemplation of his marriage to Sarah, so it is not revoked if he remarries.

On David's Death:

• Sarah receives £75,000 immediately
• Sarah receives the use and benefit of the house and its income for life
• The £325,000 discretionary trust is available to support Sarah or benefit David's children
• David's children receive £100,000 immediately and inherit the house on Sarah's death
• The pension passes directly to the children

On Sarah's Death (20 years later):

• The house passes to David's children
• Any remaining discretionary trust funds pass to David's children
• Sarah's own estate (£50,000 plus any gifts) passes under her will to her own children

Result: David's children inherit approximately £600,000, Sarah was secure for life, and IHT liability was minimized.

This is achievable planning. It requires honesty, legal clarity, and professional advice—but it is not complicated once understood.

Reviewing Existing Wills After Remarriage: A Critical Checklist

If you are recently remarried or in a new partnership, review your will immediately:

1. Was this will made before my current marriage or partnership? If yes, it may be revoked (if marriage occurred).
2. Does it reflect my current wishes? Particularly: does it provide for my current partner? Does it protect my children from previous relationships?
3. Does it address the house? Is it held as tenants in common or joint tenants? Who inherits it?
4. Does it use trusts? A basic "everything to spouse" will is almost always inadequate for blended families.
5. Are my executors and trustees appropriate? Would they fairly balance the interests of my spouse and my children?
6. Have my circumstances changed significantly? New children, remarriage, large inheritance, business interests, or significant debts all require review.

If you answer "no" to questions 2, 3, 4, or 5, your will almost certainly needs updating.

Frequently Asked Questions

Q: If I die without updating my will after remarriage, what happens?

A: Your previous will is automatically revoked (unless it was made in contemplation of your current marriage). Your estate passes under the intestacy rules: your spouse receives the first £322,000, all personal possessions, and half the remainder; your children split the other half. This is often inadequate for blended families.

Q: Can my cohabiting partner claim on my estate if I die without a will?

A: Not under the intestacy rules. However, they may be able to claim under the Inheritance (Provision for Family and Dependants) Act 1975 if they were financially dependent on you. This requires court action and is uncertain and expensive. Make a will naming them.

Q: How much IHT will I pay on assets passing to a life interest trust?

A: None, on the first death, if the trust is for a spouse or civil partner (spouse exemption applies). But on the surviving spouse's death, the underlying assets are included in their estate and may be subject to IHT if their total estate exceeds their nil-rate band (currently £325,000).

Q: Can I change my will after I remarry?

A: Yes, absolutely. You can change your will at any time and for any reason. However, if you have a mutual will or a binding agreement with your spouse, you may face legal claims if you breach it. For new marriages, this is rare. But clarify the position before remarriage if you are both bringing significant assets.

Q: What if my children from my first marriage contest my will?

A: They can potentially claim under the Inheritance Act 1975 if they argue that your will does not make reasonable financial provision for them. The courts may adjust the distribution. This is another reason to plan carefully and document your reasoning—it makes it harder for claims to succeed.

Q: Should I own my house with my cohabiting partner or keep it in my name?

A: This depends on your circumstances, but for blended families, tenants in common (rather than joint tenancy) is usually preferable. It allows you to leave your share to your children and gives you more control. However, you must update your will to direct your share to your children—without a will, the intestacy rules apply and may benefit your partner instead.

Q: Do I need a solicitor, or can I use an online will service?

A: For blended families, a solicitor is strongly recommended. The structure—life interest trusts, discretionary trusts, tax planning—requires legal expertise. Online services may produce a valid will but are unlikely to provide the protections your family needs. The cost of a solicitor (£400–£1,000 for a well-drafted will) is small compared to the problems an inadequate will can create.

Q: What is the cost of setting up life interest trusts and discretionary trusts?

A: A solicitor will typically charge £500–£1,500 to draft a will with trust structures, depending on complexity. Trustee fees (if you use a professional trustee) typically range from 0.3% to 1% of trust assets annually. These costs are significant but far lower than the cost of probate disputes, IHT liability, or the heartbreak of an unplanned estate.

Conclusion: The Path Forward

Estate planning for blended families is emotionally challenging and legally complex. But it is not optional. The default—intestacy or a simple will—will almost certainly disappoint and divide your family.

The tools exist: life interest trusts, discretionary trusts, careful ownership structures, and clear wills can protect both your current partner and your children. These tools are not exotic or obscure. They are standard practice in estate planning.

What is required from you is honesty, clarity, and action. Honesty about what you want: to provide for your partner and to protect your children. Clarity about your assets and your wishes. And action: making an appointment with a solicitor and having the conversation that perhaps feels overdue.

If you are in a blended family, do not delay. Remarriage automatically revokes your previous will. Your cohabiting partner has no legal protection. Your children from a previous relationship may inherit nothing. These are not hypotheticals; they are the default outcome.

Contact an estate planning solicitor today. Have the difficult conversations with your family. Document your wishes in a properly drafted will. The investment of time and money now will preserve your family's peace and your children's inheritance.