IHT And Cohabiting Couples: Why The Unmarried Pay More And What To Do About It
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IHT and Cohabiting Couples: Why the Unmarried Pay More and What to Do About It
Unmarried couples receive none of the Inheritance Tax (IHT) protections available to spouses and civil partners. There is no spouse exemption, no transferable nil rate band, and no automatic right to inherit if a partner dies without a will. For the 2026/27 tax year, a cohabiting partner who inherits an estate above £325,000 (or up to £500,000 where the Residence Nil Rate Band applies) is taxed in exactly the same way as a stranger would be, at 40% on the excess.
I have this conversation more often than almost any other with unmarried clients who run a business together, own a home jointly, or have built up a life together over decades. The assumption that "we're as good as married" after enough years together is one of the most expensive misunderstandings in personal tax planning, and it is worth being precise about exactly where the gap sits, because some of it can be closed through planning and some of it genuinely cannot.
Why Marriage Changes the Position So Sharply
Spouses and civil partners benefit from an unlimited exemption on transfers between them, both during lifetime and on death, under section 18 of the Inheritance Tax Act 1984. A husband can leave his entire estate, however large, to his wife with no IHT due at all, provided she is UK-domiciled or deemed domiciled. On top of that, any unused nil rate band and residence nil rate band from the first death transfers to the survivor, which is why a married couple can currently shelter up to £1,000,000 between them: £650,000 of combined NRB plus up to £350,000 of combined RNRB, using the 2026/27 figures.
None of this extends to cohabiting partners, regardless of the length of the relationship, whether there are children together, or how the couple's finances are actually run day to day. There is no concept of "common law marriage" anywhere in UK tax law. A couple who have lived together for thirty years, raised a family, and jointly own their home are, for IHT purposes, in exactly the same position as two unrelated business partners.
What the Missing Exemption Actually Costs
Take a straightforward case. A couple have lived together for eighteen years and jointly own their home as tenants in common, each holding a 50% share worth £400,000 in total, so £200,000 each. One partner also has £150,000 in savings and investments in their sole name, and dies leaving everything to their surviving partner.
If they had been married, the entire £350,000 estate would pass free of IHT under the spouse exemption, with no tax due at all and the couple's combined nil rate bands preserved for the second death. As unmarried partners, the £200,000 property share and £150,000 of other assets fall within the deceased's own £325,000 nil rate band, so in this particular example no tax happens to be due this time, purely because the total sits under the NRB.
Move the numbers up, and the picture changes quickly: the same couple with a £600,000 jointly owned home (£300,000 each) and £150,000 of other assets faces a taxable estate of £125,000 above the NRB, and a bill of £50,000 at 40%, payable before the survivor can access the full value of what they were left. There is no unlimited exemption to fall back on, and unless the couple has children who inherit a qualifying home, the RNRB is not automatically available either.
Cohabitant IHT & Intestacy Shield: Compare, Calculate & Protect
Designed by Pro Tax Accountant, this interactive tool illustrates the stark difference in UK Inheritance Tax (IHT) between married spouses and cohabiting couples, uncovering the true cost of missing exemptions such as the spousal relief and transferable nil-rate bands. By simply entering your estimated property share and sole asset values, you can compare tax liabilities side-by-side, check how blended family rules affect the Residence Nil Rate Band, and review your rights under UK intestacy laws. Use the interactive sliders and risk scanners below to model your estate’s exposure in real time and discover actionable steps to protect your partner from an unexpected tax bill.
The RNRB Trap for Blended Families
This is the part of the position that catches even well-advised cohabiting couples off guard, and it deserves more attention than it usually gets. The Residence Nil Rate Band applies where a qualifying home passes to a direct descendant, and HMRC's guidance on the residence nil rate band defines a stepchild, for these purposes, as someone whose parent is or was the spouse or civil partner of the deceased.
That single word, spouse, does real work here. If a cohabiting partner dies leaving the family home to their partner's children from a previous relationship, and the couple were never married, those children are not stepchildren of the deceased for RNRB purposes. They are not the deceased's direct descendants at all, unless the deceased formally adopted them or was their legal guardian. A £175,000 relief that a married stepparent would take for granted simply is not available, and the estate can lose the RNRB entirely on a home passing to children the deceased may have raised for twenty years, purely because the couple never married. Where blended families are involved, I always check this specifically, because it is easy to assume the relief follows the practical parenting relationship rather than the strict legal one.
Capital Gains Tax: The Other Tax That Treats Cohabitees Differently
The gap is not confined to death. During lifetime, spouses and civil partners living together can transfer assets between themselves on a no gain, no loss basis under section 58 of the Taxation of Chargeable Gains Act 1992, so no Capital Gains Tax (CGT) arises on the transfer itself and the recipient simply inherits the original cost. HMRC's helpsheet on Capital Gains Tax for spouses and civil partners confirms this applies only where the couple are married or in a civil partnership and living together.
Cohabiting partners transferring an asset between themselves, for example one partner buying out the other's share of a jointly held property or a business asset, are treated as making a disposal at market value, and a chargeable gain can arise even though no money changes hands with a third party. This matters directly for business owners restructuring how a company or investment property is held between an unmarried couple: what would be a tax-neutral transfer between spouses can trigger a real CGT liability between cohabitees, on top of the IHT exposure described above.
Dying Without a Will: Intestacy Gives Cohabitants Nothing
Under the current intestacy rules in England and Wales, a surviving cohabitant has no automatic entitlement whatsoever if their partner dies without a valid will. Everything in the deceased's sole name, and their share of any property held as tenants in common, passes to the deceased's children first, then parents, then siblings, in a fixed statutory order that simply does not include an unmarried partner. Their only recourse is a claim under the Inheritance (Provision for Family and Dependants) Act 1975, which is discretionary, requires evidence the applicant was maintained by the deceased or cohabited with them for at least two years before death, and can involve contested court proceedings at a time of genuine grief.
Property held as joint tenants (rather than tenants in common) does pass automatically to the surviving joint owner by survivorship regardless of the will or intestacy rules, but the deceased's share is still included in their estate for IHT purposes even though it bypasses the will. This is a distinction I check on every cohabiting client's property, because the way a home is held affects both who inherits it in practice and what enters the IHT calculation, and the two questions have different answers.
UK Inheritance Tax and Cohabiting Couples Facts
Hidden Fact / Legal Reality | Impact on Unmarried Couples | Recommended Solution / Mitigation |
Common law marriage does not exist in England and Wales; cohabiting couples acquire no automatic legal rights to a partner's property, savings, pension, or income upon separation regardless of relationship duration, joint children, or domestic contributions. | Leaves partners (especially economically vulnerable ones who made non-financial or domestic sacrifices) vulnerable with no automatic financial support or equitable asset division upon separation. | The Government consultation proposes a new statutory scheme for eligible cohabitants (e.g., living together 3+ years or having children) focused on meeting financial needs and addressing hardship after separation. |
Property and joint ownership disputes are decided strictly under property and trust law (e.g., TOLATA 1996) based on ownership intentions rather than fairness or future needs. | Claims under trust/property law are complex, highly fact-sensitive, and expensive to pursue, offering limited remedy for non-financial contributions. | Cohabitants can seek guidance from legal advisors on property and trust options or monitor proposed statutory framework reforms. |
Under rules of intestacy, a surviving unmarried partner has no automatic right to inherit from a deceased partner's estate if there is no valid will. | Surviving partners face severe financial risk and hardship upon their partner's death, regardless of the length of the relationship or financial intertwinement. | Surviving partners can file a claim under the Inheritance (Provision for Family and Dependants) Act 1975, or rely on proposed government reforms to update intestacy laws for cohabitants. |
Financial vulnerability in cohabiting relationships can be compounded by domestic and economic abuse without specific statutory safeguards. | Victims and survivors face barriers to financial independence and risk severe financial hardship when a relationship breaks down. | Proposed government reform seeks to integrate enhanced legal protections into the future cohabitation framework for victim-survivors of domestic abuse. |
Lack of spousal exemption on property transfers upon death | Inheritance tax (IHT) is due if the value of the property share/estate transferred exceeds the tax-free allowance, unlike married couples who transfer tax-free. | Seek estate planning advice or utilize available tax-free allowances and structuring. |
The 2026 Consultation, and Why It Will Not Change Your Tax Position
On 5 June 2026 the government opened a consultation, A Fairer End to Relationships, running until 14 August 2026, which proposes giving qualifying cohabitants automatic rights to inherit where a partner dies without a will, broadly bringing the intestacy position closer to that of spouses and civil partners. This is worth knowing about, but it is important not to conflate it with the IHT position discussed above.
The consultation addresses succession law, meaning who is legally entitled to inherit when there is no will. It does not, at this stage, propose extending the IHT spouse exemption, the transferable nil rate band, or the transferable RNRB to unmarried couples. Even if the reforms proceed exactly as proposed, and reform in this area has a long history of consultations that do not become law, a cohabiting partner who inherits more under a future intestacy regime would still pay IHT on that inheritance in the same way they do today. Fixing who inherits is a different question from fixing how much tax is due on the inheritance, and at present only the first of those two questions is under active reform.
IHT & Cohabiting Couples: Why Unmarried Partners Pay More (and How to Protect Yourself) – UK 2026/27
This interactive guide explains why cohabiting couples in the UK face a significantly higher Inheritance Tax burden than married couples or civil partners, highlighting the absence of the spouse exemption, transferable nil-rate bands and Residence Nil Rate Band protections for the 2026/27 tax year. It sets out the practical consequences through clear comparisons, a visual chart of tax-free allowances, worked examples and specific traps such as the RNRB rules for blended families. Scroll through the sections to understand the key differences, review the step-by-step planning options available now, and expand the further-detail panels for extra context. Use it as a starting point to identify where action may be needed, then seek personalised professional advice tailored to your own circumstances.
Practical Planning Routes Available Now
None of the above is a reason for inaction, and there is more scope to manage this position than the headline gap suggests.
Make a will, and keep it current. This is the single most important step for any cohabiting couple, since it is the only way to guarantee a partner inherits anything at all rather than relying on a discretionary 1975 Act claim.
Review how property is held. Holding a home as joint tenants ensures automatic survivorship to the partner regardless of the will, though the deceased's share still counts within their estate for IHT. Tenants in common gives more control over what happens to each share but relies on the will actually directing it correctly.
Use life insurance written in trust. A life policy written into an appropriate trust for the surviving partner falls outside the deceased's estate for IHT purposes and can be paid out quickly, without probate delays, specifically to cover an anticipated IHT liability on the rest of the estate. This is one of the more efficient ways to neutralise the cash-flow problem even where the underlying tax liability cannot be avoided.
Check pension death benefit nominations. Most registered pension schemes allow an expression of wish nominating a cohabiting partner, and scheme trustees typically have discretion to pay lump sum death benefits to a nominated partner outside the member's estate. This should be reviewed and kept up to date specifically because it does not happen automatically.
Use lifetime gifting deliberately. Gifts between cohabiting partners are potentially exempt transfers in the same way as gifts to anyone else, becoming fully exempt from IHT if the donor survives seven years. This can be a genuinely useful tool for a couple with a significant age or health gap, planned properly and in good time, rather than as a deathbed measure.
Recognise what business reliefs do and do not fix. Business Property Relief and Agricultural Property Relief are available regardless of marital status, since they attach to the qualifying asset rather than the recipient's relationship to the deceased. From 6 April 2026, the 100% rate of relief is capped at £1 million per person combined across BPR and APR, with 50% relief above that cap, which affects married and unmarried business owners equally. Where a cohabiting couple run a business together, these reliefs can meaningfully reduce the exposure on the business itself, but they do nothing for the couple's home, savings, or investment assets, which remain fully exposed to the gap described above.
Consider marriage or civil partnership itself. This is not always the answer clients want to hear, but for couples with a significant estate and no objection in principle, formalising the relationship remains, by some distance, the most complete way to close the IHT gap entirely, restoring the spouse exemption, transferable NRB, transferable RNRB, and CGT no gain/no loss treatment in one step.
Scotland: A Narrower, Court-Based Route on Intestacy
Inheritance Tax itself is reserved to Westminster and applies identically to cohabiting couples in Scotland as elsewhere in the UK. What differs is the succession law route available if a partner dies without a will. Under section 29 of the Family Law (Scotland) Act 2006, a surviving cohabitant can apply to the court for financial provision from the deceased's net intestate estate, but only where the deceased died intestate, only within six months of the date of death (due to extend to twelve months once the relevant provision of the Trusts and Succession (Scotland) Act 2024 is brought into force, which has not yet happened), and only up to what the applicant would have received had they been a spouse or civil partner.
There is no equivalent right where the deceased left a will, and unlike the position in England and Wales, the court has no discretion to extend the time limit once it has passed. This is a materially tighter and more time-pressured route than the English 1975 Act claim, which makes an up to date will even more important for cohabiting couples domiciled in Scotland.
Wales follows the same position as England on both succession law and IHT, since family and succession law in this area is not devolved to the Senedd, so no separate Welsh treatment applies.
FAQs
Do unmarried partners pay more Inheritance Tax than married couples in the UK?
Yes. Unmarried partners receive no spouse exemption, no transferable nil rate band, and no transferable residence nil rate band, so an estate left to a cohabiting partner is taxed at 40% above the available thresholds in exactly the same way as a gift to an unrelated person.
Is there such a thing as a common law spouse for tax purposes?
No. There is no legal status of common law marriage anywhere in UK law, including for Inheritance Tax, Capital Gains Tax, or succession purposes, regardless of how long a couple has lived together or whether they have children.
Can my cohabiting partner inherit our family home tax free if I leave it to them in my will?
Not automatically. There is no spouse exemption for unmarried partners, so the value of the home above your available nil rate band and any residence nil rate band you can claim would be subject to IHT at 40%, even though it passes under a valid will.
Will the government's 2026 consultation on cohabitation reform fix this Inheritance Tax gap?
Not on its own. The consultation, open until 14 August 2026, proposes giving cohabitants automatic inheritance rights on intestacy, which is a succession law change about who inherits, not a change to how much IHT is due on that inheritance.
Does the Residence Nil Rate Band apply if I leave my home to my partner's children from a previous relationship?
Only if you legally adopted them or were their appointed guardian. HMRC defines a stepchild for RNRB purposes as someone whose parent is or was your spouse or civil partner, so an unmarried partner's biological children do not qualify as direct descendants unless one of those conditions is met.
Can I transfer my share of our home to my partner without triggering Capital Gains Tax?
Only spouses and civil partners living together benefit from no gain, no loss transfers. A transfer between cohabiting partners is treated as a disposal at market value and can trigger a real CGT liability, even though no cash changes hands with a third party.
What happens to my estate if I die without a will and I'm not married to my partner?
In England and Wales, your partner inherits nothing automatically under the intestacy rules; your estate passes to your children, then other blood relatives, in a fixed order. Their only route is a discretionary claim under the Inheritance (Provision for Family and Dependants) Act 1975, which requires court proceedings.
Does life insurance help with this problem?
Yes, when written into an appropriate trust. Proceeds held in trust fall outside your estate for IHT purposes and can be paid to your partner quickly, without waiting for probate, providing funds to cover any IHT liability due on the rest of the estate rather than reducing that liability itself.
Is the position different if we own our home as joint tenants rather than tenants in common?
Property held as joint tenants passes automatically to the surviving partner by survivorship regardless of the will or intestacy rules, but the deceased's share is still included in their estate for IHT purposes. How the property is held affects who receives it in practice, not whether tax is due on it.
Would getting married solve all of this?
For most couples, yes, comprehensively. Marriage or civil partnership restores the unlimited spouse exemption, transferable nil rate band, transferable residence nil rate band, and no gain, no loss CGT treatment in one step, which no combination of wills, trusts, or lifetime gifting fully replicates for an unmarried couple.
About the Author:
Adil Akhtar, ACMA, CGMA, FCMA (membership ID is 990250923) serves as CEO and Chief Accountant at Pro Tax Accountant, bringing over 18 years of expertise in tackling intricate tax issues. As a respected tax blog writer, Adil has spent more than eighteen years delivering clear, practical advice to UK taxpayers. He also leads Advantax Accountants (registered with Companies House), combining technical expertise with a passion for simplifying complex financial concepts, establishing himself as a trusted voice in tax education.
Email: adilacma@icloud.com
Disclaimer: This article sets out the general position under UK tax law for the 2026/27 tax year. The information has been checked against HMRC guidance and other official sources at the date shown above, and is reviewed when the rules change. Tax legislation is complex and outcomes depend on your individual circumstances, so this article is provided for general information and does not constitute advice on which you should act. Any figures or worked examples are illustrative. Before making any decision, obtain advice specific to your situation from a qualified professional. Pro Tax Accountant accepts no liability for loss arising from reliance on this article alone.
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