Purchasing a home with a partner is a significant milestone and, for many couples, a symbol of commitment and shared future plans. But for those who are not married or in a civil partnership, entering into such a major financial arrangement introduces unique considerations. While love may bring you together, it’s vital to ensure your legal and financial arrangements are equally secure and well-structured. With one-third of UK property purchases now being made jointly by unmarried couples, understanding the intricacies of mortgage structuring becomes ever more important.

This guide aims to demystify the key mortgage structuring options available to unmarried couples and help you make informed, secure decisions about buying a home together.

Joint Ownership versus Sole Ownership

The first major decision when purchasing a property as an unmarried couple is determining how the property will be legally owned. This is typically addressed through joint ownership, although in some scenarios, one partner may purchase under sole ownership due to financial or eligibility reasons. Each approach has its own implications, not just for mortgage structuring, but for legal rights and future obligations.

Under joint ownership, both parties share legal ownership of the property, with each name appearing on the title deeds. This ownership can be further divided into two categories: joint tenancy and tenants in common. Sole ownership involves only one party holding the legal title, though the other might still contribute to mortgage payments and upkeep costs. This option is less common for cohabiting couples and carries risks for the non-owning partner if the relationship breaks down.

Joint Tenancy

Under joint tenancy, both partners own the entire property equally. This means that if one partner were to pass away, their share automatically transfers to the surviving partner, regardless of any will that might state otherwise. Joint tenancy is generally favoured by couples with a long-term outlook who view the property as equally shared in every respect.

From a mortgage perspective, joint tenancy is straightforward. Both parties are considered jointly and severally liable for repaying the mortgage debt. This means that if one party is unable or unwilling to make payments, the other will be legally responsible for covering the full repayment amount.

However, joint tenancy may not be the best fit if either partner is contributing significantly more towards the deposit or monthly repayments, or if there’s a desire to maintain a clear record of individual financial stakes. Since both parties are presumed to have an equal share, any imbalances won’t be legally recognised unless additional documentation is in place.

Tenants in Common

Tenants in common offers a more flexible arrangement, especially for couples who want to reflect unequal contributions to the property purchase. In this scenario, each partner owns a specified share of the property, which can be documented precisely – for instance, 60/40 or even 75/25. This kind of ownership does not include the automatic right of survivorship; upon one partner’s death, their share will be distributed according to their will or, if there is no will, the laws of intestacy.

For mortgage structuring, tenants in common allows for more transparency about financial contributions. Mortgage lenders still require both individuals to be jointly responsible for repayments, but the underlying ownership proportions can be formally recorded through a deed of trust, or declaration of trust.

This arrangement also makes it easier to consider and plan for potentially complex situations such as relationship breakdowns, property sales, or refinancing. By clearly stating each partner’s share, you reduce the likelihood of future disputes and make financial separation more straightforward, should it ever become necessary.

Sole Ownership with Informal Contribution

In some cases, one partner purchases the home in their name alone – either due to income disparities, credit history issues, or to take advantage of certain first-time buyer benefits (such as if one partner owns another property). While this might relieve the pressure of joint credit assessments, it also introduces risk for the partner not named on the mortgage or title deeds.

It is possible for the non-owning partner to contribute to the deposit or mortgage repayments informally. However, without legal recognition of their contribution in a formal agreement, they may have no entitlement to any share of the property should the relationship end. In such situations, it is advisable to establish a declaration of trust and potentially a living together agreement, specifying the nature of contributions and the agreed intention behind them.

Even if one partner does not appear on the mortgage or title deeds, they might attempt to claim a beneficial interest in the property under the legal doctrine of resulting or constructive trusts. The success of such a claim typically requires substantial evidence of direct contributions towards the purchase price or mortgage payments, and is often subject to legal dispute and interpretation.

How Mortgage Lenders View Joint Applications

Most UK mortgage lenders allow joint applications from unmarried couples. The key requirement is that both parties have the legal right to reside in the UK and meet the financial eligibility standards. When applying jointly, lenders assess both income levels, debt obligations, and credit scores to determine borrowing capacity.

Lenders typically do not distinguish between married and unmarried applicants, though the difference becomes significant if the relationship ends or if one party wishes to sell or exit ownership. As both individuals are equally responsible for the mortgage, lenders will pursue both for any missed payments or arrears, regardless of any personal arrangements between the couple.

That’s why it is crucial to agree in advance how repayments will be shared, and what plan is in place if either partner is unable to meet their portion of future payments. Many lenders may even recommend legal advice or require documentation showing the agreed financial structure between co-owners.

Using a Declaration of Trust

One of the most important legal instruments for unmarried couples buying a home together is the declaration of trust. This document outlines each party’s specific contributions to the purchase price, including deposits, mortgage repayments, and any capital improvements made to the property during ownership.

The declaration of trust can also set out the plan for how proceeds from a future sale should be divided. This provides a legally enforceable basis for distributing the equity based on the agreed ownership shares and helps protect both parties’ investments.

For couples opting for tenants in common ownership, creation of a declaration of trust is particularly advisable. It may also help third parties—such as conveyancers, courts, or HMRC—understand the true ownership structure if questions arise later.

Living Together Agreements (Cohabitation Agreements)

A living together agreement, also known as a cohabitation agreement, complements the declaration of trust. While the trust focuses on the financial inputs and ownership shares, the cohabitation agreement sets out the broader expectations and responsibilities of both partners while living together.

This can include how living expenses are split, how decisions about maintenance and repairs are made, and what the agreed plan is if the relationship ends. While not automatically legally binding, courts may consider them if well-drafted and freely entered into with full understanding and legal advice from both parties.

Having both agreements in place reduces ambiguity and can preserve amicable outcomes in case of disagreements. It enables couples to address emotionally sensitive situations within the framework of pre-agreed plans, rather than in the emotionally charged aftermath of relationship breakdown.

Stamp Duty Implications for Unmarried Couples

When jointly purchasing a property, you’ll want to understand any potential stamp duty land tax (SDLT) liabilities. Unmarried couples are treated as individuals for SDLT purposes.

If both buyers are first-time purchasers, they may benefit from first-time buyer relief, meaning no SDLT is due on properties up to a certain threshold. However, if one partner already owns a property or has a previous ownership history, the surcharge for additional property owners may apply, potentially increasing the SDLT liability by 3%.

It’s essential to fully disclose previous property ownership when applying for SDLT reliefs, as false claims or errors can lead to penalties and interest charges. Consulting a solicitor or tax adviser can help clarify individual liabilities and avoid unexpected costs.

Exit Planning: What Happens if You Separate or Sell

Planning for an exit scenario may seem unnecessarily pessimistic while taking such a big step with your partner, but it is one of the most critical aspects of responsible property co-ownership.

If a couple decides to separate, the process of selling or transferring ownership of the property can be complex, particularly where the mortgage is in joint names. Most lenders will not remove one person from a joint mortgage without a full affordability assessment demonstrating that the remaining individual can assume the debt independently.

A property can be sold and proceeds split according to the ownership shares if outlined in the declaration of trust. If one party wishes to stay, they will usually need to remortgage into their sole name — something that may not be possible in all cases depending on income and creditworthiness.

Disputes about selling, staying, or the division of equity can often require mediation or legal intervention. Having well-drafted agreements in place can help navigate these challenging circumstances with clarity and minimise emotional as well as financial strain.

Inheritance Rights and Estate Planning

Unlike married couples, unmarried partners do not automatically inherit each other’s assets, including property. If both names are on the title deed in a joint tenancy arrangement, survivorship rules ensure the home passes to the other partner. However, tenants in common arrangements require formal measures to ensure the surviving partner inherits their share.

Without a legal will, the deceased partner’s share of the property may be inherited by their next of kin, such as parents or siblings, which can lead to unintended consequences. Drafting a will is therefore essential for any unmarried couple sharing property ownership.

It’s also worth considering the implications of inheritance tax (IHT). Unmarried couples do not benefit from the IHT spouse exemption, meaning that if one partner dies and passes their share of the property to the other, the recipient may face a tax bill on what they inherit above the threshold.

Final Thoughts

Buying a home together is a meaningful milestone, but for unmarried couples, it must come with clear documentation, open communication, and legal foresight. From choosing the right ownership structure and securing appropriate mortgage terms to drafting declarations of trust and cohabitation agreements, each step can help protect both your investment and your relationship.

By planning ahead and seeking expert advice, you not only avoid future complications but also build a stronger foundation for the life you’re creating together—one that respects both your emotional and financial commitments.