Millions of couples living together across the UK could face unexpected financial losses if they split up, with experts warning that too many people still wrongly assume they have legal protection09:32, 23 May 2026Millions of unmarried couples across the UK could be walking into a costly financial trap without realising it – and consumer experts warn the risk is being consistently underestimated.‌This warning comes as cohabitation continues to rise sharply across the UK, with millions of households now sharing homes, bills and financial commitments without the legal safeguards that marriage provides.‌3.6 million couples now living together unmarriedAccording to the latest Office for National Statistics (ONS) data, there are around 3.6 million cohabiting couples in the UK, making unmarried couples one of the fastest-growing family types in the country.‌At the same time, marriage rates have continued a long-term decline, meaning more people are building shared financial lives without formal legal protection.Experts say this has created a growing “protection gap” – where couples are financially intertwined, but not legally safeguarded if a relationship ends.‌Why there is a dangerConsumer writer and MoneyMagpie Vicky Parry is warning that too many people still do not understand how exposed unmarried couples are financially, particularly when they have lived together for years or shared major expenses such as rent, mortgages and household purchases.is warning that too many people still do not understand how exposed unmarried couples are financially, particularly when they have lived together for years or shared major expenses such as rent, mortgages and household purchases.Time and again, cases seen in consumer reporting show people are surprised by how quickly costs mount after a breakup – and how little legal recourse they actually have.‌Recent comments from Sam Thompson, who described the practical cost of rebuilding parts of his home following a separation, highlight how even relatively straightforward breakups can carry significant financial consequences.The hidden cost of splitting upWhen unmarried couples separate after living together, the financial impact is rarely a single bill – it is a chain reaction of costs that can escalate quickly.These often include:‌replacing furniture and household goodscovering full rent or mortgage payments alonepaying new rental depositsduplicating household bills and subscriptionsmoving and storage costsEven in amicable separations, the total cost can easily run into thousands of pounds, particularly where homes and shared purchases are involved.No such thing as 'common law marriage'One of the most persistent myths in the UK is that couples gain legal rights after living together for a certain period.‌This is not true.There is no such thing as “common law marriage” in England and Wales.That means unmarried couples do not automatically have:‌rights to each other’s propertyentitlement to financial support after separationpension sharing rightsinheritance rights without a willInstead, legal outcomes depend entirely on ownership and formal legal documentation.Why so many couples are now exposedThe rise in cohabitation has been driven by:‌high housing costsrising private rentslater marriage trendsreliance on dual incomes to afford propertyAs a result, more couples are financially committing early – sharing homes, signing joint contracts and pooling money long before legal protections are considered.Experts warn this creates a situation where financial lives are deeply entangled, but legal rights are not.‌The hidden imbalance after separationAnother overlooked issue is the long-term financial imbalance that can build within relationships.One partner may:reduce working hoursrelocate for the other’s careertake on more unpaid domestic workdelay career progression‌Unlike divorce, unmarried couples have limited legal recognition of these sacrifices, meaning financial outcomes after separation can be uneven.How couples can protect themselvesExperts say the key is preparation, not pessimism.Recommended steps include:‌Cohabitation agreement Sets out how money, property, bills and responsibilities are shared, and what happens if the relationship ends.Declaration of trust (property ownership) Essential where deposits or mortgage contributions are unequal, as it legally records ownership shares.Make a will Unmarried partners do not automatically inherit without one.‌Maintain financial independence Separate savings and emergency funds can reduce exposure if circumstances change.The consumer warningThe key concern, consumer experts say, is that many couples only discover how limited their legal protection is after a relationship ends.With cohabitation now at record levels, the financial risks are becoming more widespread – and potentially more expensive.Article continues belowFor millions of households, the biggest shock is not the breakup itself, but discovering too late that no legal safety net exists when an unmarried relationship ends.