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In brief:
- There were 781,000 blended families in England and Wales at the 2021 Census, and around 1.1 million children were living in one, yet only 24% of UK adults with stepchildren have made a will, according to a STEP survey published May 2026
- Under intestacy rules in England and Wales, stepchildren have no automatic right to inherit if a step-parent dies without a will. Only marriage or formal adoption changes that, and only 12% of UK adults know that marriage automatically cancels an existing will
- 41% of parents paying child maintenance are supporting two or more children, and 21% of those are paying into more than one household, a direct sign of how often UK family finances now stretch across more than one home
You’ve merged the school run. You’ve merged the Christmas list. You’ve probably had at least one conversation about whose surname goes on what. But has anyone actually sat down and talked about the money?
Blended families, households formed after divorce, separation, or bereavement where at least one partner brings children from a previous relationship, are common in the UK. At the 2021 Census, there were 781,000 step-families in England and Wales, and around 1.1 million children were living in one. And yet the financial side of blending a family, wills, maintenance, whose name is on what, gets talked about far less than the emotional side.
Here’s what the data actually shows, and where the honest gaps are too.
How common is this, really?
According to the Office for National Statistics’ analysis of Census 2021, there were 781,000 step-families in England and Wales, of which 547,000 had dependent children living in them. Just over half of those, using ONS’s specific technical definition (a couple with at least one shared child together plus at least one stepchild), qualify as genuinely “blended” families rather than simple step-families.
8.8% of dependent children, roughly 1.1 million, were living in a step-family in 2021. That’s actually down slightly from 9.7% in 2011, though the ONS notes its methodology likely undercounts larger, more complex households, so treat this as a floor rather than a precise figure.
One more thing worth knowing: children in step-families were 3.5 times more likely to be living with a cohabiting couple than a married one. Which matters, because cohabiting couples in the UK have materially fewer automatic legal protections than married ones, something we’ll come back to.
The will most step families don’t have
Here’s the single most important fact in this entire post: under English and Welsh intestacy rules, stepchildren have no automatic right to inherit anything if a step-parent dies without a will. Only biological children, legally adopted children, or a formal act of adoption change that. Everyone else, however close, however long they’ve lived under the same roof, gets nothing by default.
A STEP (Society of Trust and Estate Practitioners) survey of 2,000 UK adults, published May 2026, found that 24% of UK adults with stepchildren have no will at all. Among practitioners surveyed for the same report, 41% said they’d seen a rise in disputes specifically within blended step-families, and 71% named complex blended families as the leading cause of business succession and inheritance planning challenges they now handle. 68% said the most common source of conflict is between children or stepchildren and a surviving parent or step-parent.
Perhaps the most quietly dangerous stat in the whole survey: only 12% of UK adults know that getting married automatically cancels any existing will. If you wrote a will before you remarried, and haven’t reviewed it since, there’s a good chance it’s not valid anymore, and if that’s the case, your estate will be distributed under intestacy rules, the exact rules that leave stepchildren out.
This is a single, though authoritative, survey rather than something independently replicated, so treat the precise percentages as indicative rather than definitive. But the underlying legal position, that stepchildren have no automatic inheritance rights, is settled law, confirmed directly on GOV.UK’s own guidance. If you want the full picture on this, our guide to understanding UK intestacy laws covers exactly how the rules work if there’s no will in place.
Money moves across more than one household
Blended families rarely involve just one household’s finances. Often there’s an ex-partner, a child maintenance arrangement, sometimes more than one.
According to DWP’s Child Maintenance Service statistics, covering the quarter to March 2026, 1.1 million children in Great Britain are covered by a CMS arrangement, managed across 810,000 individual arrangements for 730,000 paying parents. 41% of those paying parents have two or more qualifying children, and of those, 21% are paying into more than one separate household. That’s a direct, measurable sign of just how often UK family finances now stretch across multiple homes rather than one.
It’s worth being precise about what this data does and doesn’t tell us: CMS doesn’t label any of its arrangements as “blended family” specifically, so this is a proxy, not a direct measurement. But it’s the clearest available signal that multi-household finances are now a normal, not exceptional, part of UK family life.
On compliance: of the paying parents managed under CMS’s “Collect and Pay” service (used where a direct, informal payment arrangement between parents hasn’t worked), 77% paid something in the quarter to March 2026, and 54% paid more than 90% of what was due. £791.2 million has gone unpaid since CMS began in 2012, around 7% of everything owed. If you’re the parent receiving maintenance and relying on it as part of your household budget, it’s worth building some cushion into your planning for the portion that doesn’t arrive reliably.
The cost of raising children across households
Raising a child in the UK is expensive under any family structure. According to CPAG and Loughborough University’s 2025 research, the full cost of raising a child from birth to 18 is around £250,000 for a couple, and £290,000 for a lone parent. We covered this in detail in our full breakdown of the cost of raising a child in the UK.
No UK study has isolated the specific extra cost of supporting children across two separate households, maintaining two homes, potentially duplicating some costs like bedrooms, clothes, or school supplies, while splitting others like the core maintenance payment. That’s a genuine gap in the research. What we can say with confidence is that the general cost of raising children is already high, and splitting that cost delivery across two households, rather than concentrating it in one, adds a layer of coordination that first-marriage families simply don’t have to manage.
Where the honest gaps are
We’d rather tell you plainly where solid UK data doesn’t exist than stretch a general-population stat to sound blended-family-specific. Four areas came up short in our research:
How blended-family couples actually manage joint versus separate money. There’s no UK survey that specifically looks at how couples in blended families structure their bank accounts and household finances, despite this being one of the most common practical questions couples in this situation ask.
Whether blended families argue about money more than first-marriage families. No UK study directly compares financial conflict rates between the two. The closest available data point, a 2013 Marriage Foundation study, found that people remarrying were statistically less likely to divorce again than first-time marriers, but that measures divorce risk, not day-to-day money friction, and it’s now over a decade old.
Blended-family-specific housing and mortgage challenges. No major UK lender or the ONS has published research specifically on how blended families navigate combining two households or getting a mortgage as a remarried couple.
Blended-family-specific life insurance and protection gaps. No major UK insurer has published dedicated research here either. The closest usable data point is general, not blended-family-specific: research via MoneySuperMarket found that 11% of UK adults still have an ex-partner named in their will whom they no longer want to benefit, and only 23% of people who’ve had a will have gone back to update it after a breakup. Life insurance beneficiaries sit outside your will entirely and need to be updated separately, directly with the insurer, which is a very real and very practical risk if you’ve remarried and never checked.
What blended families can actually do
Given where the strong data points and where the gaps sit, a few things are worth acting on directly:
Check your will exists, and check it’s valid. If you married or remarried after writing a will, there’s a good chance that will no longer applies. Given that only 24% of stepparents have a current will at all, and only 12% of people even know marriage cancels an old one, this is the single highest-impact thing most blended families haven’t done.
Decide deliberately whether stepchildren inherit, don’t assume the law will sort it out. It won’t. Intestacy rules exclude stepchildren by default. If you want a stepchild to inherit from you, that has to be written down explicitly, either in a will or through formal adoption.
Update your life insurance beneficiary nomination separately from your will. These are two different legal documents, and updating one doesn’t update the other. If you’ve remarried, check who’s named on your policy directly with the insurer.
Talk about maintenance and multi-household costs as a shared household topic, not a private one. With 41% of paying parents supporting more than one qualifying child and a fifth of those splitting payments across separate households, this is common, not unusual. Bringing it into the open household budget conversation, rather than treating it as one partner’s private business, tends to reduce friction later.
If you’re cohabiting rather than remarried, know that your legal protections are different. Research by Resolution, the family law body, found 47% of cohabitees are unaware they lack the same legal rights as married couples if they separate. Given how much more likely children in step-families are to be living with a cohabiting couple, this is worth understanding clearly rather than assuming “common law marriage” offers protection it doesn’t legally provide.
The bottom line
Blending a family well is mostly about the everyday stuff, patience, fairness, making everyone feel like they belong. But the financial side needs its own deliberate attention, because the legal default in the UK doesn’t automatically protect stepchildren, and the paperwork most people assume is sorted usually isn’t.
None of this requires a complicated fix. A will review. A beneficiary check. One honest conversation about money that crosses two households instead of one. Small, specific actions, done early, protect the family you’ve actually built.
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