英国遗产税对非婚伴侣的保护：同居伴侣如何避免高额遗产税

Inheritance Tax (IHT) in England and Wales applies a 40% charge on estates valued above the nil‑rate band of £325,000, a threshold that has remained frozen since 2009. For married couples and civil partners, the rules offer a crucial relief: any unused nil‑rate band can be transferred to the surviving spouse, effectively doubling the allowance to £650,000. However, for the estimated 3.5 million cohabiting couples in the UK (Office for National Statistics, Families and Households, 2023), this spousal exemption does not apply. When one partner dies without a will or proper planning, the surviving partner can face an immediate IHT bill on assets passing above the single £325,000 threshold—a tax liability that married couples in identical financial circumstances would entirely avoid. The disparity is stark: HMRC data for the 2021/22 tax year recorded over 27,000 IHT-paying estates, a figure that cohabitation campaigners argue would be significantly lower if cohabiting partners received equal treatment. This article outlines the specific tax risks, the legal mechanisms available to mitigate them, and the practical steps unmarried partners should take to protect their inheritance.

The Spousal Exemption Gap: Why Cohabiting Partners Are Taxed Differently

The core issue lies in Inheritance Tax law as defined by the Inheritance Tax Act 1984. Section 18 provides an unlimited exemption for assets passing between spouses or civil partners upon death. This exemption is automatic and applies regardless of the estate’s size. For cohabiting couples—often referred to as “common‑law partners” in popular parlance, though no such legal status exists in England and Wales—this exemption is not available.

The practical consequence is that any bequest made to an unmarried partner is treated as a chargeable transfer. If the deceased’s total estate exceeds the £325,000 nil‑rate band, the portion passing to the surviving partner above that threshold is subject to IHT at 40%. This includes jointly owned property held as “tenants in common” (where each partner owns a distinct share) and individually owned assets such as savings, investments, or a sole‑name property.

HMRC statistics for 2021/22 show that the average IHT bill on non‑spousal estates was approximately £214,000 (HMRC, Inheritance Tax Statistics, 2023). While this figure includes all estates, it underscores the potential liability for a surviving cohabitant inheriting a mid‑value home and modest savings. Without planning, a partner could be forced to sell the family home to settle the tax bill.

The Nil‑Rate Band and the Residence Nil‑Rate Band for Unmarried Partners

The nil‑rate band (NRB) of £325,000 is the fundamental allowance. For married couples, unused NRB transfers to the surviving spouse, creating a combined £650,000 threshold. For cohabiting partners, no such transfer exists. If Partner A dies with an estate of £500,000 and leaves everything to Partner B, the IHT calculation is straightforward: £500,000 – £325,000 = £175,000 chargeable at 40%, yielding a tax bill of £70,000.

The residence nil‑rate band (RNRB) adds a further £175,000 (for 2024/25) where a main residence is passed to direct descendants—children or grandchildren. Crucially, the RNRB is not available when assets pass to a cohabiting partner who is not a direct descendant. This means an unmarried partner inheriting the family home cannot claim the additional allowance, potentially increasing the taxable portion by a further £175,000.

For a cohabiting couple with a home worth £500,000 and other assets of £100,000, the total estate of £600,000 would attract IHT of £110,000 after the single NRB. A married couple with the same assets would pay zero IHT due to the spousal exemption and NRB transfer.

Life Insurance in Trust: A Practical Shield Against the IHT Bill

One of the most effective and straightforward solutions is life insurance written into an appropriate trust. The policy is taken out on the life of the partner with the larger estate, with the death benefit paid directly to the surviving partner via the trust. Because the proceeds are held in trust, they do not form part of the deceased’s estate for IHT purposes.

The trust structure ensures the payout is available to cover the IHT liability quickly, often within weeks of death, without requiring the sale of assets. For a couple where one partner owns the home in their sole name, a level‑term life insurance policy for the expected IHT amount—say £100,000 over a 20‑year term—can be cost‑effective. Premiums for a healthy 50‑year‑old non‑smoker might range from £30 to £60 per month, depending on cover amount and term length.

It is essential that the policy is written into trust from the outset. If the policy is simply owned by the deceased and paid to the surviving partner as a beneficiary, the payout becomes part of the estate and may itself be subject to IHT. A solicitor or specialist IHT planner can draft the trust deed, and the policy can be arranged through standard insurance providers. For cross‑border situations involving UK and non‑UK assets, some families use channels like Airwallex global account to manage multi‑currency premium payments or estate‑related transfers efficiently.

Wills, Gifts, and the Seven‑Year Rule: Strategic Lifetime Planning

A properly drafted will is the cornerstone of any cohabiting partner’s IHT plan. Without a will, the intestacy rules apply, which in England and Wales give no automatic entitlement to an unmarried partner. The partner may receive nothing, and the estate could pass to blood relatives, potentially triggering a larger IHT charge if those relatives are not exempt beneficiaries.

Lifetime gifts offer another avenue. Under the “seven‑year rule,” gifts made more than seven years before death are generally exempt from IHT, provided they are outright gifts with no retained benefit (such as continuing to live in the gifted property rent‑free). For a cohabiting couple, a partner could gift cash or assets to the other partner, reducing their estate value. However, if the donor dies within seven years, the gift is added back to the estate for IHT calculation, with taper relief applying after three years.

The annual gift allowance of £3,000 per tax year (plus small gifts of up to £250 per person) can be used to transfer modest sums each year without IHT implications. Regular gifts from surplus income, if properly documented, are also exempt. For a couple with a combined estate approaching the NRB threshold, a systematic gifting programme over several years can meaningfully reduce the eventual IHT liability.

Joint Ownership Structures: Tenants in Common vs. Joint Tenancy

How a cohabiting couple holds property has direct IHT consequences. Joint tenancy means each partner owns the whole property jointly; upon death, the deceased’s share automatically passes to the surviving joint tenant by survivorship. This can be problematic if the surviving partner is not a spouse, as the full value of the home may be included in the deceased’s estate for IHT purposes.

Tenants in common allows each partner to own a distinct, severable share (often 50/50, though unequal splits are possible). Upon death, the deceased’s share passes according to their will, not automatically to the survivor. This structure enables the couple to use the nil‑rate band more effectively. For example, if the home is worth £500,000 and each partner owns a 50% share, the deceased’s £250,000 share falls within their £325,000 NRB, leaving the full £75,000 of unused allowance to cover other assets.

However, careful planning is required. If the deceased’s will leaves their share to the surviving partner, the spousal exemption still does not apply, and the share is simply added to the survivor’s estate—potentially pushing them over the NRB. A more sophisticated approach involves leaving the deceased’s share into a discretionary trust for the surviving partner and other beneficiaries, keeping it outside the survivor’s estate while allowing them to live in the property.

Cross‑Border Considerations for Non‑UK Domiciled Partners

For couples where one partner is domiciled outside the UK, the IHT landscape becomes more complex. UK domicile rules determine which assets are subject to IHT. A person domiciled in the UK is liable on their worldwide estate; a non‑UK domiciled individual is generally liable only on UK‑situated assets.

If a non‑UK domiciled partner dies leaving UK property to their cohabiting partner, the UK property is chargeable. However, the nil‑rate band still applies, and the same planning tools—trusts, life insurance, gifts—remain available. For couples with assets in multiple jurisdictions, professional advice is essential to avoid double taxation and to ensure that trusts or wills are valid under both UK and foreign law.

The UK government’s proposed changes to domicile rules, announced in the 2024 Spring Budget, may abolish the concept of domicile for IHT purposes and replace it with a residence‑based test from April 2025. This would mean that long‑term UK residents—including many cohabiting partners—could become subject to IHT on their worldwide assets regardless of domicile. Staying informed of legislative changes is critical for cross‑border couples.

FAQ

Q1: Can a cohabiting partner inherit the family home without paying IHT if the estate is under £325,000?

Yes, provided the deceased’s total estate (including the home, savings, and other assets) does not exceed the £325,000 nil‑rate band, no IHT is payable. However, if the home is held in the deceased’s sole name and the estate exceeds this threshold, the portion above £325,000 passing to the partner is taxed at 40%. For a home valued at £400,000 with no other assets, the IHT bill would be £30,000 (£400,000 – £325,000 = £75,000 × 40%). Married couples with the same home would pay zero IHT due to the spousal exemption.

Q2: What happens if a cohabiting partner dies without a will—does the surviving partner inherit automatically?

No. Under the intestacy rules of England and Wales, an unmarried partner has no automatic right to inherit. If the deceased has no children, the estate passes to parents or siblings. If there are children, the partner may receive a statutory legacy of £270,000 (for deaths after 6 February 2020) plus half the remaining estate, but only if the deceased had children. Without a will, the partner could receive nothing, and the estate may be distributed to blood relatives, potentially triggering IHT if those relatives are not exempt beneficiaries.

Q3: How long does the surviving partner have to pay the IHT bill after the death?

IHT must be paid to HMRC by the end of the sixth month after the deceased’s death (i.e., within six months). If the tax is not paid by that date, HMRC charges interest at 7.75% (as of April 2024) on the outstanding amount. For estates where the main asset is a home, executors can apply to pay IHT in instalments over up to 10 years, with interest charged on the deferred portion. However, the first instalment is still due within six months of death.

References

• Office for National Statistics (2023). Families and Households in the UK: 2023.
• HMRC (2023). Inheritance Tax Statistics: 2021/22 Data.
• Inheritance Tax Act 1984, Sections 18, 8A–8D (Residence Nil‑Rate Band).
• Ministry of Justice (2022). Intestacy: Who Inherits When Someone Dies Without a Will.
• HM Treasury (2024). Spring Budget 2024: Proposed Changes to Domicile Rules for Inheritance Tax.