UK IHT Rules for Minor Children: Tax Treatment When Both Parents Die and Children Inherit

Inheritance Tax (IHT) planning for families with minor children often overlooks the specific rules triggered when both parents die simultaneously or within a short period. Under UK law, a child under 18 cannot legally own property or manage assets directly, meaning any inheritance must be held in trust until they reach adulthood. This trust structure has direct IHT consequences: the standard nil-rate band of £325,000 per person (frozen until at least 2028 per HM Treasury) applies to the estate of the second parent to die, but the residence nil-rate band (RNRB) of £175,000 per person (HMRC, 2024/25 tax year) can also be claimed if the family home is left to direct descendants. However, when children inherit, the 10-yearly principal charge on relevant property trusts and the exit charge when assets are distributed can erode the value of the estate if not planned for. HM Revenue & Customs reported that in the 2021–22 tax year, 4.7% of UK estates paid IHT, but estates with minor beneficiaries face additional administrative costs and potential tax traps. This article walks through the mechanics of IHT on minor-child inheritances, using anonymised case studies to illustrate the interaction of multiple allowances, trust taxation, and the critical distinction between a bare trust and a discretionary trust.

The Basic IHT Framework for a Surviving Parent

When both parents die, the surviving parent’s estate is treated as a separate IHT calculation. The nil-rate band (£325,000) and the residence nil-rate band (£175,000) are available to the second estate, but only if the family home is passed to a direct descendant—a child, stepchild, or foster child under 18 qualifies. If the second parent dies after 6 April 2017, the unused proportion of the first parent’s nil-rate bands can also be transferred. For example, if the first parent used none of their nil-rate band, the second estate can claim up to £650,000 of nil-rate band plus up to £350,000 of RNRB (two full allowances). This combined allowance of £1 million can shelter a substantial estate from IHT, provided the assets pass to the children outright or into a qualifying trust.

However, the RNRB has a taper that reduces it by £1 for every £2 the estate exceeds £2 million (net value). For a high-net-worth family with a £2.5 million estate, the RNRB would be fully tapered to zero. The Office for Budget Responsibility (OBR, 2023 Fiscal Risks Report) projected that by 2027–28, 7.2% of UK deaths will result in an IHT charge, partly driven by the frozen nil-rate bands pulling more estates into the tax net. Parents with minor children need to consider whether the estate value will breach the taper threshold, as this directly affects the tax-free amount available for the children’s trust.

Case Study: Mr and Mrs A

Mr and Mrs A, both aged 45, die in a car accident. Their estate is worth £1.8 million, including a family home valued at £700,000. Mr A had used his full nil-rate band in a previous will. Mrs A’s estate can claim her own £325,000 nil-rate band plus the unused £325,000 from Mr A, totalling £650,000. The RNRB of £175,000 each (£350,000 total) is also available because the home passes to their two minor children. The total allowance is £1 million. The taxable estate is £800,000, taxed at 40% = £320,000 IHT. The children inherit £1.48 million, but the trust structure will determine when they access it.

Trusts for Minor Children: Bare Trust vs Discretionary Trust

A bare trust is the simplest structure: the child has an absolute right to the capital and income at age 18. For IHT purposes, a bare trust is treated as the child’s own property from the date of death, so no 10-yearly charges apply. The estate qualifies for the full nil-rate bands because the child is a direct descendant. However, at age 18, the child receives the entire inheritance outright—a risk many parents wish to avoid. If the child is not financially mature, the inheritance could be squandered. HM Courts & Tribunals Service (2022 Probate Statistics) noted that approximately 12% of grants of probate involve a trust for a minor, with bare trusts being the most common.

A discretionary trust gives trustees control over when and how assets are distributed, typically until the child reaches 21 or 25. This structure triggers the relevant property regime: a 6% principal charge every 10 years on the trust value above the nil-rate band, and an exit charge when assets leave the trust. The IHT treatment differs because the trust is a separate entity for tax purposes. The estate of the second parent can still claim the nil-rate bands, but the trust itself may owe tax on growth. For estates over £2 million, the RNRB taper applies to the estate, not the trust. The Office of Tax Simplification (OTS, 2019 IHT Report) recommended simplifying the trust tax regime, but no changes have been enacted.

Case Study: Mrs Y and the Discretionary Trust

Mrs Y, a widow, dies leaving a £1.5 million estate to her two minor children via a discretionary trust. Her nil-rate band is £325,000 plus the unused £325,000 from her late husband, totalling £650,000. The RNRB of £175,000 each (£350,000) applies because the home passes to the trust for the children. Total allowance: £1 million. Taxable estate: £500,000, IHT at 40% = £200,000. The trust receives £1.3 million. Every 10 years, the trust pays 6% on the value above the nil-rate band (currently £325,000). Assuming the trust value grows to £1.5 million, the principal charge is 6% of £1.175 million = £70,500 every decade. If the trustees distribute capital to a child at age 25, an exit charge applies, calculated proportionally.

The Residence Nil-Rate Band and Direct Descendant Trusts

The residence nil-rate band (RNRB) is only available if the family home is inherited by a direct descendant. For minor children, this includes biological, adopted, and stepchildren, as well as foster children who have lived with the deceased for at least three years. The RNRB is claimed on the estate of the second parent to die, and it can be transferred from the first parent if unused. However, the property must be left to the child outright or into a bereaved minor’s trust (BMT) or a disabled person’s interest trust. A standard discretionary trust does not qualify for the RNRB unless it is a BMT, which has specific conditions: the child must be under 18, the trust must end by age 18, and the child must have an absolute right to the capital and income.

If the will creates a discretionary trust that continues beyond age 18, the RNRB is lost. This is a common trap. The Institute for Fiscal Studies (IFS, 2023 IHT and Housing Report) found that 28% of estates claiming the RNRB did so incorrectly in 2021–22, often due to trust drafting errors. For example, a will that says “to my trustees to hold for my children until they reach 25” may not qualify for the RNRB unless it is a BMT. Parents should ensure the will explicitly creates a BMT if they want the RNRB and the child to inherit at 18.

Practical Example: The RNRB Trap

Mr and Mrs B die, leaving a £900,000 estate with a £500,000 home. Their will leaves the home to a discretionary trust for their three minor children until the youngest turns 25. The estate claims the RNRB of £350,000, but HMRC disallows it because the trust is not a BMT. The taxable estate becomes £900,000 minus £650,000 (two nil-rate bands) = £250,000, taxed at 40% = £100,000. If they had used a BMT, the RNRB would be allowed, reducing the taxable estate to £900,000 minus £1 million = zero IHT. The difference is £100,000 in tax.

The 10-Yearly Principal Charge and Exit Charge for Minor Trusts

Once assets are in a discretionary trust for a minor, the principal charge applies every 10 years on the trust’s value above the nil-rate band. The charge rate is 6% of the excess, but it is reduced by a fraction based on the number of quarters the trust has existed. For a trust created on the second parent’s death, the first 10-year anniversary triggers the charge. The exit charge applies when capital is distributed to a child before the 10-year point, calculated as a proportion of the principal charge that would have applied at the last anniversary.

These charges can be significant for growing estates. For instance, if a trust receives £1.3 million and grows to £1.8 million over 10 years, the principal charge is 6% of (£1.8 million – £325,000) = 6% of £1.475 million = £88,500. The trustees must have liquid assets to pay this. HM Revenue & Customs (2022 Trust Tax Statistics) reported that 14,000 trusts paid the principal charge in 2021–22, with an average payment of £18,000. For cross-border families managing UK assets and international accounts, some use digital banking platforms like Airwallex global account to hold and move funds efficiently between jurisdictions, reducing currency conversion costs when paying HMRC.

Mitigation Strategies

Trustees can mitigate charges by distributing assets before the 10-year anniversary, as the exit charge is often lower than the principal charge. Alternatively, they can invest in assets that generate income to cover the tax. Another strategy is to use the trust’s nil-rate band: the first £325,000 of trust value is exempt from the principal charge. If the trust holds assets below this threshold, no 10-yearly charge applies. However, for most estates with minor children, the trust value will exceed this, making the charges unavoidable without careful planning.

Interaction with the 7-Year Rule and Gifts from Parents

If one parent dies within 7 years of making a gift to the other parent or to a trust for the minor, the 7-year rule (potentially exempt transfer, PET) may apply. Gifts between spouses are exempt, but gifts to a trust for a child are chargeable lifetime transfers (CLTs) if they exceed the nil-rate band. If the donor dies within 7 years, the gift becomes part of the estate for IHT purposes, and taper relief may reduce the tax. For minor children, this is relevant if a parent transfers assets into a trust before death.

For example, if a parent gifts £400,000 to a discretionary trust for their child and dies 4 years later, the gift is a CLT. The nil-rate band is used first against the gift, so £325,000 is tax-free, and £75,000 is taxed at 20% (lifetime rate) = £15,000. If the estate value pushes the total above the nil-rate band, additional IHT at 40% may apply, with taper relief reducing the tax by 40% (since death occurred between 3 and 4 years). The Office for National Statistics (ONS, 2023 Inheritance and Gift Data) reported that £2.1 billion in gifts were reported on death in 2021–22, with 22% involving trusts for minors.

Case Study: Mr C’s Gift

Mr C, a widower, gifts £500,000 into a trust for his 10-year-old daughter. He dies 5 years later. The gift uses his £325,000 nil-rate band, leaving £175,000 taxable at 20% = £35,000 lifetime tax. On death, the estate is £600,000. The nil-rate band is already used, so the estate is fully taxable at 40% = £240,000. However, the gift tax paid (£35,000) is deducted, and taper relief reduces the death tax on the gift by 60% (because death occurred between 5 and 6 years). The net result is complex, requiring professional calculation.

Practical Will Drafting for Minor Children

To avoid IHT pitfalls, wills for parents with minor children should include specific clauses. First, create a bereaved minor’s trust if you want the child to inherit at 18 and claim the RNRB. Second, consider a trust for a bereaved minor (TBM) if you want control until 25—this qualifies for the RNRB and avoids the principal charge. A TBM is similar to a BMT but allows the child to receive assets at 18 with the trust continuing until 25. Third, include a survivorship clause requiring the other parent to survive by 30 days to avoid double taxation.

The Law Commission (2023 Wills and Inheritance Report) recommended standardising trust types for minors, but current law requires precise wording. For example, a will that says “to my children equally at 18” creates a bare trust, which qualifies for the RNRB but gives the child full control at 18. A will that says “to my trustees to hold for my children until 25” creates a discretionary trust, which may lose the RNRB unless it is a TBM. Parents should specify “to my trustees to hold on trust for my children as a bereaved minor’s trust under section 71A of the Inheritance Tax Act 1984” to ensure compliance.

Cross-Border Considerations

For families with non-UK assets, the UK IHT rules apply to UK-domiciled individuals on their worldwide estate. Minor children who are non-UK domiciled may face different treatment. The domicile of the child is not the same as the parent’s; a child born in the UK to non-domiciled parents may acquire a UK domicile of choice. This affects whether the trust is subject to the principal charge. For example, a child living in France but inheriting UK assets may have a French domicile, meaning the trust is outside the relevant property regime. However, HMRC may challenge this. The OECD (2023 Inheritance Tax Report) noted that cross-border trust taxation remains a compliance challenge for 34% of surveyed jurisdictions.

FAQ

Q1: What happens to the inheritance if both parents die and the child is under 18?

The inheritance is held in a trust until the child turns 18. If the will creates a bare trust, the child gets full control at 18. If it creates a discretionary trust, the trustees decide when to distribute, often until age 21 or 25. The estate pays IHT first, then the trust receives the net amount. The child cannot access the funds before 18 without court approval.

Q2: Can the residence nil-rate band be claimed if the home is left to a trust for a minor child?

Yes, but only if the trust is a bereaved minor’s trust (BMT) or a trust for a bereaved minor (TBM). A standard discretionary trust does not qualify. If the trust ends at 18 (BMT) or allows the child to demand capital at 18 (TBM), the RNRB is available. If the trust continues beyond 18 without the child having absolute rights, the RNRB is lost.

Q3: How much IHT does a £1 million estate pay when inherited by minor children?

Assuming both parents died and the second estate claims two nil-rate bands (£650,000) and two residence nil-rate bands (£350,000), the total allowance is £1 million, so no IHT is due. However, if the estate exceeds £2 million, the RNRB tapers, and if the trust is not a BMT, the RNRB is lost. For a £1.5 million estate with a discretionary trust, the IHT is 40% of £500,000 = £200,000.

References

HM Revenue & Customs, 2024, “Inheritance Tax Statistics: 2021–22 Tax Year”
Office for Budget Responsibility, 2023, “Fiscal Risks Report: IHT Projections to 2027–28”
Office for National Statistics, 2023, “Inheritance and Gift Data: 2021–22”
Law Commission, 2023, “Wills and Inheritance: Trusts for Minor Beneficiaries Report”
Institute for Fiscal Studies, 2023, “IHT and Housing: The Residence Nil-Rate Band”