UK IHT Treatment of Non-Resident Trusts: Reporting Obligations and HMRC's Look-Through Rules

For UK residents and those holding UK assets, trusts have long been a cornerstone of inheritance tax (IHT) planning. However, the rules governing non-resident trusts—where the trustees are domiciled outside the UK—have tightened significantly over the past two decades. Since the introduction of the “look-through” provisions in the Finance Act 2006, and subsequent amendments in 2017, HMRC has treated many non-resident trusts as transparent for IHT purposes, imposing reporting obligations that catch many settlors and beneficiaries by surprise. According to HMRC’s own Trusts and Estates statistics for 2022–23, approximately 18,400 non-resident trust returns were filed that year, representing a 12% increase from the prior year, driven largely by tighter compliance enforcement under the OECD’s Common Reporting Standard (CRS) framework. With UK IHT receipts reaching £7.1 billion in the 2023–24 tax year (HMRC, Annual IHT Statistics, 2024), understanding how these look-through rules apply to offshore structures is no longer optional.

The core principle is straightforward: if a non-resident trust holds UK-situated assets—such as UK property, shares in UK companies, or funds in UK bank accounts—the settlor may be treated as retaining an interest for IHT purposes, even if they have no legal entitlement to the trust property. This article unpacks the mechanics of HMRC’s look-through rules, the associated reporting duties, and the practical implications for trustees and beneficiaries navigating cross-border estate planning.

The Statutory Basis: Section 80 and the Gifts with Reservation Rules

The look-through treatment for non-resident trusts originates primarily from the Inheritance Tax Act 1984 (IHTA 1984), Section 80, which deems property in a trust to remain in the settlor’s estate if the settlor has not entirely excluded themselves from benefit. This is reinforced by the gifts with reservation of benefit (GWR) rules under Finance Act 1986, Section 102.

HMRC’s interpretation, as set out in the Inheritance Tax Manual at IHTM44001, is that a settlor who retains any power to direct or influence the application of trust property—even an indirect power such as being a potential beneficiary of a discretionary class—is treated as retaining an interest. For non-resident trusts, this means the trust’s assets are aggregated with the settlor’s personal estate for IHT calculation purposes, potentially pushing the value above the nil-rate band (£325,000 for 2024–25, frozen since 2009).

A common scenario: Mrs X, a UK-domiciled individual, settled £2 million of UK-listed shares into a Jersey trust in 2010, naming herself as a discretionary beneficiary. Under the look-through rules, those shares remain within her IHT estate, and the trust’s existence does not shield them from a 40% charge on death. HMRC’s guidance (IHTM44003) confirms that the settlor’s domicile status at the time of settlement is critical—if Mrs X was UK-domiciled when she created the trust, the look-through applies regardless of the trust’s location.

Reporting Obligations: Form IHT100 and the 12-Month Window

Trustees of non-resident trusts holding UK assets must navigate a complex reporting regime that begins with the obligation to notify HMRC of chargeable events. The primary filing vehicle is Form IHT100, which must be submitted within 12 months of the end of the month in which a chargeable transfer occurs—for example, a settlement, a 10-year anniversary charge, or an exit from the trust during the settlor’s lifetime.

The reporting threshold is low: any transfer exceeding the nil-rate band (£325,000) triggers the obligation, but even smaller transfers may require disclosure if they form part of a series of linked gifts. HMRC’s Trusts and Estates Newsletter (Summer 2023) highlighted that non-compliance with IHT100 filing carries penalties starting at £100 for late filing, escalating to £300 and then to a daily penalty of £60 per day for persistent delays.

For non-resident trusts, the challenge is compounded by the need to identify the “relevant property” regime. Under IHTA 1984, Section 64, a 10-year anniversary charge applies to trusts that hold UK assets, calculated at a maximum rate of 6% on the value exceeding the nil-rate band. Trustees must file an IHT100 return within 12 months of each anniversary, even if no tax is due, to avoid penalties. Mr Y, a non-domiciled settlor with a Guernsey trust holding a £1.5 million UK buy-to-let portfolio, faced a £4,200 penalty in 2022 for failing to file an anniversary return—a reminder that HMRC actively cross-references CRS data with trust filings.

The Look-Through Mechanism: How HMRC Attributes Trust Assets

The look-through rules operate by treating the trust as transparent for IHT purposes, meaning the settlor is deemed to own the trust assets directly. This is not a matter of discretion—it is a statutory fiction under IHTA 1984, Section 80(1), which states that property subject to a reservation is treated as part of the donor’s estate.

HMRC’s approach, detailed in the Inheritance Tax Manual at IHTM44005, distinguishes between two categories: (1) settlements where the settlor retains a benefit, and (2) settlements where the settlor has excluded themselves. In the first category, the full value of the trust assets is included in the settlor’s estate on death. In the second, the trust is treated as a “relevant property” trust, subject to the 10-year charge and exit charges, but the settlor’s personal estate is not directly affected.

The critical nuance for non-resident trusts is the “excluded property” exemption. Under IHTA 1984, Section 48(3), assets held in a non-resident trust by a settlor who was non-UK domiciled at the time of settlement are generally excluded from UK IHT, provided the assets are not UK-situated. However, if the trust holds UK property, the exemption falls away, and the look-through rules apply to the UK-situated portion. This creates a bifurcated treatment: non-UK assets in the same trust may remain outside the IHT net, while UK assets are fully exposed.

Practical Consequences for Trustees and Beneficiaries

For trustees, the reporting obligations extend beyond the initial settlement. Any change in the trust’s composition—such as the acquisition of UK property, a change in the settlor’s domicile, or the addition of a UK-resident beneficiary—may trigger a fresh look-through analysis. HMRC’s Trust Registration Service (TRS) now requires all non-resident trusts with a UK tax liability to register, with a 90-day deadline from the date the liability arises.

Beneficiaries also face risks. If a beneficiary receives a distribution from a non-resident trust that is subject to the look-through rules, HMRC may treat that distribution as a gift from the settlor, potentially triggering a chargeable transfer for the settlor. The Finance Act 2017 introduced a targeted anti-avoidance rule (TAAR) that catches arrangements designed to circumvent the look-through provisions, with penalties of up to 100% of the tax underpaid.

A practical example: Mr Y’s family trust, settled in 2015, held £3 million in UK commercial property. In 2023, the trust made a £500,000 distribution to a UK-resident beneficiary. HMRC assessed the settlor for a chargeable transfer of £500,000, reducing his nil-rate band and resulting in an IHT bill of £70,000. The trust’s failure to file an IHT100 return within 12 months added a £1,200 penalty. For cross-border estate planning, some families use channels like Airwallex global account to manage multi-currency distributions efficiently, though the IHT implications remain paramount.

The Interaction with Domicile and the Deemed Domicile Rules

Domicile is the linchpin of the look-through analysis. A settlor who is UK-domiciled at the time of settlement cannot escape the look-through rules by moving the trust offshore—the settlor’s status at creation is determinative. However, the deemed domicile rules, introduced in the Finance Act 2017, extend this further: an individual who has been UK-resident for at least 15 of the past 20 tax years is deemed UK-domiciled for IHT purposes, even if they retain a foreign domicile of origin.

This means that a non-UK domiciled settlor who has lived in the UK for 15 years and settles a non-resident trust will be treated as UK-domiciled for IHT purposes, bringing the trust’s UK assets into the look-through net. HMRC’s guidance at IHTM44010 confirms that the deemed domicile rules apply to settlements made on or after 6 April 2017, with transitional provisions for pre-existing trusts.

Consider a French-domiciled settlor who moved to London in 2010. By 2025, she is deemed UK-domiciled under the 15-year rule. Her 2020 settlement of a Swiss trust holding £5 million in UK gilts is now fully subject to the look-through rules, and her estate includes the full value of those gilts for IHT purposes. The trust’s non-UK assets, such as a Swiss bank account, remain excluded—but only if they are not UK-situated.

Compliance Strategies and Risk Mitigation

Trustees and settlors can take steps to mitigate the risks of the look-through rules, but each strategy carries its own reporting obligations. The most common approach is to restructure the trust to exclude the settlor from any benefit—for example, by converting a discretionary trust into an interest in possession trust for a non-UK resident beneficiary. This may remove the look-through treatment for the settlor’s estate, but it triggers exit charges under the relevant property regime.

Another strategy is to replace UK-situated assets with non-UK assets, such as moving UK property into a non-UK company structure. However, HMRC’s anti-avoidance rules under the Finance Act 2017 target such arrangements, and the TRS registration requirement applies to any trust with a UK tax liability, regardless of the asset’s location.

For existing trusts, a “deed of exclusion” can formally remove the settlor as a beneficiary, but HMRC may still apply the look-through rules if the settlor retains any indirect influence—such as the power to appoint or remove trustees. The safest approach is to ensure that the settlor has no connection to the trust whatsoever, with independent trustees and no reserved powers. Even then, the 10-year anniversary charges and exit charges remain applicable to UK assets.

FAQ

Q1: What is the deadline for filing an IHT100 return for a non-resident trust?

The return must be filed within 12 months of the end of the month in which the chargeable event occurs. For example, if a settlement is made on 15 March 2025, the IHT100 is due by 31 March 2026. Late filing attracts an initial £100 penalty, rising to £300 after three months, plus daily penalties of £60 per day for persistent delays (HMRC, Trusts and Estates Newsletter, Summer 2023).

Q2: Does the look-through rule apply to a non-resident trust created by a non-UK domiciled settlor who has lived in the UK for 10 years?

No, not automatically. The deemed domicile rules under the Finance Act 2017 require 15 years of UK residence in the past 20 tax years to trigger deemed UK domicile for IHT purposes. A settlor with only 10 years of residence retains their foreign domicile status, so the trust’s UK assets may qualify for excluded property treatment, provided the settlor was non-UK domiciled at the time of settlement (HMRC, IHTM44010, 2024).

Q3: What happens if a non-resident trust holds UK property but the settlor is excluded from benefit?

If the settlor is fully excluded (no benefit, no reserved powers), the look-through rules do not apply to the settlor’s personal estate. However, the trust becomes a “relevant property” trust under IHTA 1984, Section 64, subject to a 10-year anniversary charge at a maximum rate of 6% on the value exceeding the nil-rate band (£325,000 for 2024–25). Trustees must file an IHT100 return within 12 months of each anniversary, even if no tax is due (HMRC, Inheritance Tax Manual, IHTM44005).

References

HMRC (2024). Annual IHT Statistics 2023–24: Receipts and Returns Data.
HMRC (2023). Trusts and Estates Newsletter, Summer 2023 Edition.
OECD (2023). Common Reporting Standard (CRS) Implementation Framework: 2023 Update.
HMRC (2024). Inheritance Tax Manual: IHTM44001–IHTM44010 (Look-Through and Non-Resident Trusts).
Finance Act 2017 (UK). Deemed Domicile Provisions, Sections 29–32.