OS v DT [2025] EWFC 156, explained in plain English: the child maintenance case for parents with equal care

What actually happened in OS v DT?

The names are initials because the case was heard in private and published in anonymised form — standard practice in the family court, and the judge's rubric — the formal notice on the front of a published judgment setting the rules for reporting it — forbids identifying the family. What we know is what the published judgment tells us.

OS (the wife) and DT (the husband) were a London couple, both with careers in finance. They married in 2014, had three children — all aged ten or under at the time of the hearing, all at fee-paying schools — and separated in 2023.

Here's the part that matters. In early 2024, through mediation, they agreed to divide the children's time exactly equally: Monday and Tuesday nights with their mother, Wednesday and Thursday nights with their father, weekends alternating, school holidays split down the middle. The judgment records that "this is broadly what has happened in the last year or so". Neither parent disputed it. That agreed, clearly recorded, actually-followed equal split is the foundation everything else rests on.

The divorce came to a final hearing before His Honour Judge Edward Hess over four days in April 2025. Most of it was about dividing the family's money (over £9 million of assets — this was a big-money case, which is worth remembering later). But tucked inside was the question that earned this judgment its place in the textbooks.

The wife asked the court to order the husband to pay child maintenance of £15,000 per child per year, plus all the school fees. The husband's team said the court had no power — no jurisdiction, in the legal jargon — to make any child maintenance order, other than for school fees.

That sounds like a technicality. It isn't. It goes to the heart of how child maintenance works in England and Wales.

What did the court decide — and why?

Some quick background, in plain English.

Since the Child Support Act 1991, child maintenance has mostly been taken away from judges and given to the state system — today's Child Maintenance Service (CMS), which took over new cases from the Child Support Agency (CSA) in 2012–13. Sections 8(1) and 8(3) of that Act generally prevent a court from making a child maintenance order in any case where the CMS "would have jurisdiction" to do an assessment. There are known exceptions — for example, where a parent lives abroad, or "top-up" orders where the paying parent's income is above the CMS maximum of £3,000 per week gross.

But exactly equal care creates a puzzle. The CMS's own rules — Regulation 50 of the Child Support Maintenance Calculation Regulations 2012 — mean an assessment can only be made if one parent provides, in the regulation's words, "day to day care to a lesser extent" than the other. If care is exactly equal, neither parent provides less. So there is no "non-resident parent", no "qualifying child", and nothing for the CMS to assess. (I've written a full plain-English guide to Regulation 50 if this is your situation.)

So: if the CMS can't act, does the court's old power come back to life? Before this case, the leading practitioner textbooks flagged that as an open question. Nobody had a clear answer.

Judge Hess gave one:

"…my view is that in a situation where there is an established agreement or order which clearly provides for parents to have exactly equal care for a child, either party can apply to the court for a child periodical payments order and that party does not first have to make an application to the CMS." — OS v DT [2025] EWFC 156 (B), paragraph 52(viii)

("Child periodical payments" is simply the court's term for regular child maintenance.)

Three details of the reasoning are worth holding onto.

First, the Child Benefit point. The CMS often treats whoever receives Child Benefit as the parent with care by default. The judge noted that this default "will give way to clear 'evidence to the contrary'" — and an established agreement or order for exactly equal care is exactly that kind of evidence.

What if your care is exactly equal but nothing says so in writing? Then you're outside the fast lane this judgment describes. OS v DT turned on an established agreement — mediated, written down, followed by both parents. Where equal care is real but undocumented or disputed, the route back is the ordinary one: putting evidence of equal day-to-day care in front of the CMS, and if necessary a tribunal — the tribunal decides that question on all the evidence, and the Upper Tribunal has set out how in some detail (LP v SSWP & EM [2024] UKUT 302). Whether a court would accept evidenced-but-never-agreed equal care as removing the CMS's jurisdiction is a question OS v DT leaves open. Which is the quiet lesson again: the agreement that opens the door is a document. If you can't get the agreement, the next best thing is a record clear enough to put the real pattern in front of a tribunal.

Second, you don't need the CMS's permission slip. Unlike top-up cases, where you must get a maximum-income assessment from the CMS before going to court, the judge found no requirement to obtain formal confirmation from the CMS that it lacks jurisdiction. A parent with a clearly established equal-care arrangement can go straight to court.

Third — and this is the key bit — jurisdiction is not an order. The judge was careful:

"None of the above suggests that a court should make a child periodical payments order, but it has jurisdiction so to do, and may do so if the facts justify it." — paragraph 52(x)

And on these facts, he didn't. The husband was about to take redundancy with little ongoing income; both parents were left with substantial capital; the care burden was equal. No ongoing maintenance was ordered. The judge did, however, order the husband — who held more capital and the stronger earning capacity — to pay three-quarters of the children's school fees, with the wife paying one quarter.

One more thing gives this judgment unusual weight for a Family Court decision at circuit judge level: with the approval of Mr Justice Peel, the judge formally certified it as citable in other cases. That was deliberate. This judgment was written to be relied on.

What does OS v DT change for parents with 50/50 care?

The practical shape of the law now looks like this:

• Care slightly unequal (even 52/48): the CMS has jurisdiction. One parent is the "paying parent", and shared care is handled through the night-count bands — I've covered how those work, and how to evidence them, in How to show 50/50 shared care to the CMS. And a hard truth that surprises people: the receiving parent's income is irrelevant to the formula. The calculation runs on the paying parent's gross income only — so a 48% parent can be paying a 52% parent who earns far more, and the rules are working exactly as designed. (The government reviewed the calculation, and told Parliament in June 2026 that it would not be reforming rates and thresholds "at this time". That is the law today.)
• Care exactly equal, and clearly established: the CMS has no jurisdiction. No CMS assessment can be made — and if one parent wants maintenance anyway (say, where incomes are very different), the route is a court application, which the court may or may not grant on the facts.

That is a genuine cliff edge, and it puts enormous weight on a question that sounds simple and isn't: is your care exactly equal, and can that be shown clearly?

Notice what decided OS v DT. Nobody had to give evidence about whose weekend it was. The equal split lived in a mediated agreement, clearly recorded, and actually followed for over a year. The judge's operative phrase — "an established agreement or order which clearly provides" for exactly equal care — is doing the heavy lifting. Clarity, not luck, is what made the jurisdiction question answerable.

Most separated parents don't have that clarity. Most of us live in the land of "roughly half the time" — and "roughly" is precisely where disputes start. The distance between about half and a figure you can state and show is where the effort is required.

What does OS v DT mean for how you keep your care record?

First, the limits. This case gets oversold, so it's worth being clear:

• It's one case, on its own facts — a big-money London divorce where equal care was agreed, not disputed. Your facts will differ.
• It's a circuit judge decision. It's citable and carefully reasoned, and it drew support from earlier tribunal and court decisions — but it doesn't bind higher courts.
• It is not a route to a windfall. The court in OS v DT had the power and chose not to use it. "The court can" never means "the court will".

None of that shuts you out if you've never had a mediated agreement or a court order. Most shared-care families haven't. The ordinary route is still open: show the CMS, and if it comes to it a tribunal, the care you actually provide, from a record kept as you go. OS v DT is one door; the evidence route is the main one.

What the case genuinely rewards is clarity about your care arrangement. If that's the lesson, here's what it looks like in practice:

If you have a court order or written agreement for equal care — keep it safe, and keep to it. In OS v DT, the established agreement was the clarity. An order that says one thing while real life does another protects nobody.

If you don't — then the only thing that can make "exactly equal" (or 50/50, or 52/48) more than an assertion is a record kept as you go. Not a reconstruction from memory the week the dispute starts: a truthful, contemporaneous, slightly boring daily record. The point isn't the numbers. It's that anyone can check how they were kept.

And a line I'll keep repeating across these guides: a record bent towards a conclusion is worth nothing — to a tribunal, a court, or you. The only record worth keeping is the true one, written down as it happens. If your true record shows equal care, OS v DT is why the precision matters. If it shows something else, better to know that from your own notebook than from someone else's assessment.

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