Marriage is not just a personal or romantic milestone; it is a legal relationship that comes with powerful financial and tax benefits, many of which are not available to cohabiting couples. While the emotional bond between long-term partners may be identical regardless of marital status, the legal and fiscal frameworks in place are not.
For couples living together without marrying, this gap can create profound vulnerabilities in areas such as taxation, pensions, inheritance, and ownership of property. As such, it’s vital for cohabiting partners, particularly those building lives and assets together, to understand what marriage changes, and what protections they may be missing.
This article explores the full financial, legal, and estate planning implications of marriage under the law in England and Wales in 2025, while offering guidance for cohabiting couples to take meaningful legal steps toward security and peace of mind.
Finances
While marriage may be a deeply personal decision, it can also make compelling financial sense. The legal bond between spouses opens up a suite of tax efficiencies and cost-saving opportunities that are simply not available to cohabiting partners. From allowances that reduce annual tax bills, to exemptions that preserve wealth in later life, the UK tax system continues to reward married couples in tangible, measurable ways:
- The Marriage Allowance:
Many married couples can take advantage of the simple tax benefit known as the UK’s Marriage Allowance. Even though the amount saved may seem nominal, the allowance is one of the first real benefits that newlyweds experience and is a strong financial indicator of the tax system’s support for marriage.
- Capital Gains Tax (CGT):
More significant than income tax relief, however, is the Capital Gains Tax exemption on transfers between spouses. This allows married couples to gift assets such as property, shares, or business interests to one another without triggering an immediate tax liability. Unmarried couples do not benefit from this exemption. Any asset transferred between them may be treated as a market-value disposal for CGT purposes, triggering immediate tax, even if no cash changes hands.
This flexibility is especially powerful for:
- Planning around property sales, where married couples can shift ownership stakes in anticipation of a disposal;
- Making use of lower-income spouses’ tax bands to reduce CGT by shifting gains to the lower taxpayer;
- Managing investment portfolios with greater agility.
- ISA and Pension Death Benefits:
Marriage brings further advantages when it comes to long-term savings and retirement planning. For example, a spouse can inherit the tax-free status of an Individual Savings Account (ISA) via an Additional Permitted Subscription (APS) allowance, enabling them to top up their own ISA without affecting their personal limits (irrespective of whether the Spouse actually inherited the ISA).
Private pensions and workplace pensions often include death-in-service or lump-sum death benefits. These are typically passed automatically to a surviving spouse, often free of inheritance tax and sometimes entirely outside the estate. However, unmarried partners are often not automatically entitled and, in some cases, must be specifically named as beneficiaries to access this protection, which is not always guaranteed or upheld.
In both cases, the structure of marriage significantly simplifies succession and preserves tax efficiency in the transition of wealth between partners.
Mortgage lending, joint insurance, and cost efficiencies
From a practical financial perspective, many lenders view married applicants more favourably than unmarried ones. This is not codified in law, but is based on the perceived stability of the relationship, shared liability, and the enforceability of financial agreements. Married couples may be offered better mortgage rates, enjoy lower premiums on joint insurance policies, and access financial products unavailable to individual applicants.
There is also protection in the event of relationship breakdown: where cohabitees face significant hurdles asserting claims to property or financial support, the divorce framework ensures fair division of matrimonial assets and, where appropriate, ongoing financial support through spousal maintenance.
Legal and Inheritance Protections
While the financial benefits of marriage are often clear-cut in the realms of tax and banking, some of the most significant advantages only become apparent in the context of inheritance, succession, and life events. These protections are less visible in day-to-day life — but they can determine whether a surviving partner remains financially secure or faces unexpected loss.
This legal infrastructure is where marriage functions not just as a personal commitment, but as a protective contract, offering clarity in the most emotionally and financially vulnerable moments: serious illness, bereavement, or separation.
One of the most generous and impactful legal benefits of marriage is found in the UK’s Inheritance Tax (IHT) framework. As of 2025, IHT is charged at 40% on estates valued above £325,000 – a figure that hasn’t changed for several years, despite rising property and asset values. For those with children, this can increase to £500,000 with the £175,000 residence nil rate band for homeowners.
However, transfers between married couples are entirely exempt from IHT, both during life and on death. This means that a surviving spouse can inherit the entire estate of their partner, tax-free, no matter how large it is. This exemption not only avoids an immediate tax charge, but also defers IHT until the second death, offering families more time and flexibility to plan.
In addition, if the first spouse doesn’t use all of their available IHT allowances, the unused portion can be passed to the survivor. This includes:
- The nil-rate band, currently £325,000; and
- The main residence nil-rate band, currently £175,000
This means that, so long as certain requirements are fulfilled, married couples can effectively transfer up to £1 million tax-free to their children or grandkids. The additional residence nil-rate band is also available to step-children, meaning that a person without biological lineal descendants could still benefit from the relief if benefiting the children of their spouse.
In addition, with the changes to both Business Relief and Agricultural Property Relief scheduled for April 2026, there will be a further planning opportunity for married couples as each person is expected to have an additional £1 million IHT free allowance specifically for certain classes of asset. In order to maximise this allowance, it may be worthwhile for one spouse to transfer assets to the other so that they each utilise the allowance.
This structuring opportunity is not just a tax break – it often determines whether family assets such as the family home or business can be passed down unaffected. For unmarried couples, these routes are either blocked or severely limited.
The risk to unmarried partners
In contrast, cohabiting couples, regardless of how long they’ve been together, do not benefit from spousal exemption, and any inheritance passed between them may be fully subject to IHT if it exceeds the £325,000 threshold. In addition, any unused allowance is not transferrable between cohabiting couples. This can cause significant hardship, especially where the surviving partner has no independent legal right to shared property or sufficient funds to cover the tax.
Even more striking is the impact of intestacy. If someone dies without a valid Will, their estate is distributed according to fixed legal rules, and those rules make no provision for unmarried partners. The entire estate could pass to children, parents, or siblings, while the surviving partner is left with nothing, regardless of the depth of the relationship.
Whilst there is provision in law for a cohabitee in certain circumstances to bring a claim against the estate for failing to make adequate provision, this is often a time consuming and expensive process if the heirs in intestacy do not wish to co-operate.
The takeaway is simple: unmarried couples must take active steps to protect each other, starting with a well-drafted Will.
What Unmarried Couples Can Do
For those who do not wish to marry, or who are not yet ready, the law does offer tools that can mitigate some of the risks.
A cohabitation agreement can be used to set out each partner’s rights in relation to shared assets, contributions to household expenses, and responsibilities should the relationship end. It is particularly valuable where one partner owns the home or where there is an imbalance in income or wealth.
A carefully prepared Will is even more crucial. It is the only way to ensure that an unmarried partner inherits under law, and can help reduce the likelihood of costly disputes with family members. In addition, a well drafted Will can assist in mitigating the adverse IHT position of unmarried partners, ensuring that adequate provision is made for the surviving partner as efficiently as possible, albeit it cannot exactly replicate the favourable position of married couples.
Is marriage worth it, financially?
From a legal and financial standpoint, the answer for many couples is yes.
Marriage may not define a loving or committed relationship – but it does carry legal weight and tax power that cannot be matched by informal arrangements. The benefits range from tangible cost savings to profound protections during moments of vulnerability.
In tax terms alone, the advantages of Inheritance Tax exemption, Capital Gains Tax flexibility, ISA and pension succession rights, Transferable tax allowances, and Legal certainty in ownership and death can amount to hundreds of thousands of pounds over a lifetime.
For those who remain unmarried, legal planning becomes essential. Without it, even long-standing partners may find themselves legally unrecognised at the moment they need protection most.
Take control of your future
Whether you’re considering marriage for its legal and financial benefits, planning for the future with a cohabitation agreement, or simply need guidance on inheritance and asset protection, it’s important to make informed decisions rooted in clear legal understanding.
At Buckles, we work with individuals and couples across all walks of life to structure their affairs in a way that safeguards their relationships, wealth, and wishes – both now and in the future.
Speak to one of our experienced solicitors today to ensure your partnership, however it’s defined, is protected by the law.
