Ex disputing CMS and making rival Child Benefit claim in 50/50 care

Good luck @fixatedplanet

Youre not greedy. It’s not a race to the bottom bottom. CMS is a scandal of our times.. it’s shocking things are still shit for single parents and the societal expectation on single mothers is insane.. there is still no equality and even less if you are a single mother in 2026. Best of luck Xo

Child maintenance should be based on the costs of raising the children and the needs of the child. Once you separate or divorce, you shouldn't then benefit from the other parents income. Assuming your DC's needs were being met just fine, you now have another £800 per month, to spend on what? I'm not surprised he's pushing back. A case where an otherwise healthy co-parent relationship might have been messed up through greed.

As far as I know if you both have equal number of nights i.e 50/50 then CMS look to determine who is primary carer. You might need to Google this. So it is possible if the tribunal determine there is no primary carer then yes they could close your CMS case.
You may need to apply to the courts for top up maintenance as he is high earner as the £156k is the maximum income CMS can take into account.
Would it be possible to withdraw your CMS claim, ask him to leave you with the child benefit and discuss if he can contribute more seeing as though he earns over double your salary. If the Tribunal close your case you haven't lost anything

If a higher earner in a together partnership demanded a 50/50 split of child related costs, there would be cries of LTB. No idea this is considered greed when a relationship breaks down

I think this is a very fair point, although he did already offer to pay more than half of childcare related costs and op wants cms to get even more than that — implies that the cms would be supporting her costs as well.

I actually think it’s fair far an ex spouse to still support their exs standard of living, at least in some cases. Before marriage I able to support myself financially to a good standard and could have supported 2 kids alone with effort. Due to decisions made jointly during marriage I’m no longer in that position. If we split I would have to move very far away to a much cheaper area, even then I’d have a harder time supporting myself. These were joint decisions. Why should he be able to opt out of the consequences whenever he likes and leave me to bear them alone? I think it’s fair that he share the financial implications long term (especially as those same decisions have hugely supported his career so he’s in a better earning position than he was before). I don’t at all resent any of this, they’re the best choices for our family, but only under the assumption that we act as a single unit. I don’t think he should have the option to push all the negatives onto me alone whenever he wants to.

All of that is a case for spousal maintenance, however. It’s not appropriate to use child maintenance payments to improve your own financial position or standard of living. But if that’s the only legal route possible… I can sympathize with why the op might want to try this.

Particularly if a mother has sacrificed career progress, hours to support said children in earlier years (and part of the agreement within the marriage)

Nobody seems to really have any understanding or inclination.
They just wear you down and hope you give up actually what we should do is just give them the kids let them have them
We can be the Disney parents that weekend and then maybe we’d be on 156 grand if we were unencumbered

The ex shouldn't have to supplement his ex's household just because he earns higher. He pays 50% of his children's costs and also has them 50% of the time...as he should

It's called child maintenance. Not supporting your ex maintenance. Parents should be contributing to the whole of a child's needs proportionate to income. Sure, a disparity in incomes will likely mean different sized properties, older vehicles, more or less luxurious holidays. But chdren are a joint enterprise, not necessarily s 50/50 one.

If your ex earned more than the CMS limit the family court should have sorted it (as they do in high profile cases with footballers and the likes). Below the limit (currently 156k) CMS will deal.

There is a stupid loophole that one year and a day after the order is given either party can go to CMS and request they deal with it. This is abused by wealthy NRP’s as it means their ex has to take them back to court again for a new order. I dealt with one woman whose ex had done it every year for 8 years in a row, and legally he was allowed.

He has them 50% of the time and pays for 50% of their food, clothing, school supplies etc. Of course he shouldn’t have to pay CM and I’m amazed CMS insist he does… You can’t demand money from him simply because he earns more, it’s there for NRP’s to pay their fair share but neither of you could be defined as a NRP since it’s 50/50.

It does make sense for him to claim.

The child benefit claim being in her name is what allowed her to claim CMS. If he gets his legally entitled claim to the child benefit sorted then she cannot use that to claim CMS against him. It very much does make sense.

Try and follow this.

CMS base their decision on who claims the child benefit.

Both of them are entitled to claim the child benefit. He let her claim all of it as she earns less. She then used it to claim CMS.

She isn’t actually entitled to both child benefit claims because he is entitled to one. It does not matter if he can’t actually get the money due to his salary - that has nothing to do with his entitlement to have his name attached to one of the child benefit claims.

She is using his goodwill against him. He let her claim both child benefits, and she has then used that as evidence to get the CMS. He is fixing it by rightfully claiming child benefit for one of the children. That is what happens in 50/50 cases with two kids. They will award one child benefit to each parent. This means she cannot then claim CMS for that child.

She isn’t entitled to CMS. She only got it awarded because he allowed her to claim both child benefits.

The difference in their salaries is not enough that a court would order maintenance to crate parity in the households.

It may very well make sense when CMS is involved. They use CB as a blunt tool for calculations. He may not be entitled to keep the £20 a week CB, but if it reduces his liability to maintenance by hundreds a month it’ll make sense for him.

CMS is payable even when 50/50 if therr is a significant difference in earnings, however, it is hard to prove and get. It relies mostly on it being proven to be 50/50 on paper but the claimant doing more of the actual parenting, i.e. doctor/dentist appointments, opticians etc whilst the other oarent doesn't do those things.

From what you have posted, he does all of that so I am not sure a tribunal will uphold your claim.

If your salary is as you state and 60k, then you should be repaying part if not all of the CB so why does it matter if he puts a claim in?

Honestly, you sound incredibly greedy

I sympathise with the huge disparity but I think you are making a huge mistake doing this. A better option would be to talk to him and ask if a solution could be found - et perhaps he takes on the full burden of things like.school uniform or clubs.

You also.dont.say what, if any, asset splits happened at the time of the divorce. Did you benefit t all there?

How should it be done then because when I was getting divorced and trying to make it part of the financial arrangement, I was told that wasn’t something that the family court deal with
When I quoted section one of the children’s act I was told that hadn’t been applicable for 30 years
You just go round and round in circles with these things until eventually you run out of money. In my experience.

Op needs a court order for payments due to his wage. Cms is just going to end up closing the case.

@fixatedplanet to follow up on my original comment this is what AI said about my query and your situation. As others have said, you are on thin ice....
Your reply is thoughtful but slightly off-target — career sacrifice is more the domain of divorce financial settlement (already concluded) than CMS, which has its own rigid formula regardless of historical contributions.

Here's a more accurate read of the situation, and why she may indeed be walking into a mess:

The CMS position

CMS calculates maintenance based on the paying parent's income and the number of nights the child spends with each parent. At 7/14 nights (exactly 50/50), the standard reduction is 50%, which is what she's getting. CMS doesn't factor in the receiving parent's income at all — so her £60k is irrelevant to the formula. That part is working as intended from her perspective.

The Child Benefit problem

This is where it gets complicated for her. CMS uses Child Benefit receipt as a proxy for "primary carer" — whoever claims it is treated as the applicant with standing. Her ex can't personally benefit from Child Benefit due to the High Income Tax Charge, but he can make a rival claim to establish which household the child is primarily associated with for CMS purposes. If HMRC awards it to him (or splits it), her CMS claim for that child is weakened or lost entirely. HMRC looks at who the child "lives with" — in a genuine 50/50 arrangement, this is genuinely contestable.

The tribunal risk

She's essentially asking a tribunal to confirm she's the primary carer when she has explicitly described a 50/50 arrangement for 4.5 years, with both parties doing equal shares. Gathering "evidence I do more" when she's already stated he does his full share on his weeks is going to be a hard sell, and potentially embarrassing if it looks like manufactured retrospective evidence against a well-documented equal arrangement.

The core tension she's not acknowledging

She turned down his offer to split shared costs (which would have cost him less) in favour of CMS (which costs him more), because he earns more. That's her prerogative, but CMS wasn't designed to redistribute income between high-earning separated parents — it was designed to ensure children aren't left financially unsupported by an absent or lesser-involved parent. In a genuine 50/50 arrangement, the policy justification gets much murkier, which is probably why he's contesting it.

She may well end up with reduced or no CMS payments, potential repayment of months already received, and legal costs for a barrister — versus the shared-costs offer she declined. That's the backfire risk.

Others have said you may succeed in court on the basis of achieving parity of lifestyle. Sounds like you need legal advice.

Having worked for CMS everything she said was accurate in terms of how it would have worked in that situation with those figures.

this OP is different with a high earning ex. That’s a different kettle of fish, but shouldn’t be done through CMS.

It makes absolutely no difference. Child benefit do not take that into consideration. He is entitled to claim it and just forgo receiving the money. The reason he is entitled is for things like that - child benefit is often used for other agencies to decide who the resident parent is. When it’s 50/50 and only one child then they will go through every detail to decide who should have it. But with 2 kids, they always split it by awarding one claim to each parent. It absolutely does not matter what the parents earn.

The fact is that she is using the child benefit claim as evidence to make CMS award her money. He will be using that as his defence - because it isn’t fair. And he will be awarded one of the child benefit claims. His salary makes no difference.

In high earning cases where one massively out earns the other courts (not CMS) will often order child maintenance so that the children have a relative parity in their lifestyle in both houses.

It’s not as simple as 50/50, or number of nights, when it’s a high value case.

Who knows most of what’s made up online made up completely so I don’t consider that to be a legal precedent set

That doesn’t matter. If they are truely 50/50 he’s entitled to one regardless. So she shouldn’t be claiming two.