Meet the Other Phone. Child-safe in minutes.

Meet the Other Phone.
Child-safe in minutes.

Buy now

Please or to access all these features

AIBU?

Share your dilemmas and get honest opinions from other Mumsnetters.

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

425 replies

fixatedplanet · 22/03/2026 14:34

Hi all,

I’m really struggling with this and could do with some advice.

We’ve had a proper 50/50 week-on/week-off arrangement for the last 4.5 years. The boys (14 and 11) split their time equally between us week on/week off and we’ve always split the costs of shared things 50/50. He does his bit when they’re with him and I do mine. It has been working fine but....

The issue is income. I earn around £60k and he earns well over the £156k threshold. Because of that, even though it’s 50/50, I applied to CMS for child maintenance so he pays his fair share (it comes out at the maximum rate, around £800 a month which is a 50% discount as he has them 7 nights out of 14). I thought that was reasonable as his salary is much higher and he should pay more than half.

He immediately challenged it with a Mandatory Reconsideration, which was rejected because I receive the Child Benefit (he gave it up due to the high income charge and then during divorce said I could have it which only seemed fair). Now he’s put in a rival Child Benefit claim for one of the children AND lodged a tribunal appeal with the CMS. He’s basically trying to get out of paying anything through CMS and I could lose some of the child benefit now!!!

We are completely 50/50. He does everything on his time and I do everything on mine. But because he earns more, he should contribute more and CMS should sort this I would have thought, I should not have to go to a tribunal.I have started to gather evidence to try and show that I do more so it gives me a good chance at the tribunal and I guess he is doing the same now. I am going to get a barrister to help out at the tribunal to try and prove I do more but he does stuff too so not sure if that will help me.

I’m worried he might actually get the Child Benefit (even though he can’t claim it himself because of the high income charge) and that the tribunal might side with him. Does he have any chance of winning that? It just doesn’t feel fair because he earns much more than me even though we share all the care equally. He did offer to cover all of the shared costs but I have said no and decided to go down the CMS route as that will be more money than simply covering the shared costs.

Has anyone been through this? Can he really do the rival Child Benefit thing and what are his chances? I guess he has lots of evidence to show that we share care equally and have done for several years but he cannot even claim it so I would miss out! And what are the chances at tribunal? Surely they will see my side of things? He has started to pay me the £800 a month now so I have had a few months payment so far so that is good at least but I am worried I might lose it or be told to give it back.

Thanks in advance.

OP posts:
JustAnotherWhinger · 22/03/2026 15:13

Usernamechanging · 22/03/2026 15:01

But it’s not the other case? It seems maintenance is due - a result of the disparity in incomes. This is fair.

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,

The disparity of income means it should be going through court. Not CMS.

Birdsongisangry · 22/03/2026 15:13

Him earning more doesn't mean you're entitled to boost your own income. It would be different if you were on a very low income, where you'd be struggling to pay for basics and he would be providing a luxurious lifestyle. But given you're on 60k I think you'd struggle to evidence that there would be a significant disparity in lifestyles to justify CMS on 50/50. Be prepared that he may well be awarded CB for one (regardless of whether he actually gets the money) and that no maintenance would be due.

BringBackCatsEyes · 22/03/2026 15:14

Usernamechanging · 22/03/2026 14:53

It isn’t greedy to expect parents to contribute to the upbringing of their children proportionate to income.

We don't know that he isn't. Say both of them spend 50% of their income on child-related expenses (running a home, education/hobbies, clothes, holidays) then that's OK, isn't it?
OP can't expect her ex to boost her household income so she can spend the same amount as her ex.

PullyDog · 22/03/2026 15:21

Why do you do more if it's 50/50? How? What are you doing?

Holdmybeermoment · 22/03/2026 15:25

There was a poster in your exact situation and we all told her not to go to CMS but she did anyway.

He challenged the child benefit and won, so they get child benefit for one child each but he earned too much so doesn’t receive the money. It’s still his claim though. Once he got the child benefit, he was able to claim CMS from her for one of the children. She could claim CMS from him for the other one. So they have to pay each other, and she ends up with a little extra.

You’re 50/50. Trying to get £800 a month from him is despicable. He will 100% win here. You’ll lose child benefit for one of the kids and he can claim CMS from you for that child.

GargoylesofBeelzebub · 22/03/2026 15:28

He will get half the child benefit. Your greed will backfire on you.

Unpaidviewer · 22/03/2026 15:30

Why would you think this is okay OP? I really hope he wins and has to pay you nothing. Disgusting behaviour.

Octavia64 · 22/03/2026 15:36

Op this could be very tricky.

income isn’t the only thing a court will take into consideration here and so you need to think through the situation as a whole.

were you married? Was there an asset split?

if you are struggling to feed and house your children while your ex is not, and you are separated rather than divorced then this is one thing.

look at the big picture.

Whaleandsnail6 · 22/03/2026 15:37

Usernamechanging · 22/03/2026 15:01

But it’s not the other case? It seems maintenance is due - a result of the disparity in incomes. This is fair.

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,

Because once you split, you are responsible for your children, not your ex partner in the majority of cases.

Whereas a "together couple" would likely have a more pool of family resources. Its a totally different scenario once the couple split.

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. I hope he does not have to pay once it goes to court as it seems he is doing right by his kids.

He also offered to pay for extra costs to reflect his higher income. He does not seem to be an unreasonable person.

Quine0nline · 22/03/2026 15:40

Who would the 14 year old prefer to tay with?

Randomuser2026 · 22/03/2026 15:41

sellingrocks · 22/03/2026 14:44

This went very very wrong for another poster and she pretty much lost custody of the children as they decided their mother was after their dads money and sided with him …..🤔

I don’t actually see why he should pay you a penny since you have true 50/50 split? You earn well enough - it’s not his fault he earns more than you…..

But it would be his fault if the kids had to go without because he can afford the difference between what OP can afford and half the cost but chooses not to bridge the gap?

“What a pity Mum can’t pay half the cost of This trip to Disney/University Fees/A car - looks like my contribution gets to be zero. Looks like I have to just go on the trip with my girlfriend, and have an even more ridiculous car. Go talk to Mum- it’s not my fault she can’t pay half of the big ideas I put in your head.”

Newyearawaits · 22/03/2026 15:41

Fedupmumofadultsons · 22/03/2026 14:49

Well honestly he had them 50/50 oaid his fair share you then got greedy for no reason but you saw a loophole .he bow is goung to take family allowance from you knowing he can't keep it .he us just reacting to your behavior. I would try and go back to original .50/50 split costs because you may be worse off and you then risk any decency between you if there is any

This
You are coming across as being very greedy OP.
He has your children 50/50 so shouldn't be paying any maintenance.
His high earnings are irrelevant, you are no longer married.
You are earning a decent salary.
Let this go OP

somanychristmaslights · 22/03/2026 15:43

Why do you feel he should still pay you money if he has them 50/50? He looks after and pays for the kids when he has them, and you should do the same.

Whaleandsnail6 · 22/03/2026 15:48

Randomuser2026 · 22/03/2026 15:41

But it would be his fault if the kids had to go without because he can afford the difference between what OP can afford and half the cost but chooses not to bridge the gap?

“What a pity Mum can’t pay half the cost of This trip to Disney/University Fees/A car - looks like my contribution gets to be zero. Looks like I have to just go on the trip with my girlfriend, and have an even more ridiculous car. Go talk to Mum- it’s not my fault she can’t pay half of the big ideas I put in your head.”

He has already offered to pay more than half of shared expences due to the difference in incomes. Op said no.

And if he wanted to take the kids to Disney, he would pay for it. He wouldn't ask op for half ..Op has already said, they are responsible for what they do in their own time.

Holdmybeermoment · 22/03/2026 15:51

Randomuser2026 · 22/03/2026 15:41

But it would be his fault if the kids had to go without because he can afford the difference between what OP can afford and half the cost but chooses not to bridge the gap?

“What a pity Mum can’t pay half the cost of This trip to Disney/University Fees/A car - looks like my contribution gets to be zero. Looks like I have to just go on the trip with my girlfriend, and have an even more ridiculous car. Go talk to Mum- it’s not my fault she can’t pay half of the big ideas I put in your head.”

Um.. what? He pays for the kids fully during his time. So if he planned a holiday, he’d pay for that fully. The OP isn’t paying half of the kid’s costs when they’re with their dad.

I think she means things like school trips, clubs, childcare etc. But he isn’t asking her to pay half the cost of him taking them on a holiday. That’s his costs. He also offered to cover their costs 100% so OP wouldn’t have to pay for any of their trips, clubs, activities etc. She said no because she wanted to claim CMS to “get more money that way.” Greed. It’s greed.

She just didn’t think it through and realise that he was giving her the child benefit out of kindness, and could go after it himself to stop her claiming CMS that she isn’t entitled to. The only reason she is entitled to CMS is because she gets the child benefit. She only gets the child benefit because he let her. They are actually both entitled to that benefit, and legally should claim for one child each (whether or not they actually receive the money due to income). She is using the child benefit as the basis for claiming CMS. Since she isn’t actually entitled to both child benefit claims, that means she isn’t entitled to CMS. He is just fixing that to stop her fraudulent claims.

You’re just making stuff up to have a go at a man. Just because he is a man. But this guy hasn’t done anything wrong. He is fully 50/50 with the kids and funds half of their joint costs plus fully funds their time with him. The OP is the money grabber here.

MrsBennetsPoorNervesAreBack · 22/03/2026 15:54

Usernamechanging · 22/03/2026 15:01

But it’s not the other case? It seems maintenance is due - a result of the disparity in incomes. This is fair.

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,

Surely it's different for a "together couple" because they're a team and resources are therefore pooled.

If the couple splits, then they each retain equal responsibility for any shared children but the higher earner shouldn't be required to subsidise the lower earners lifestyle because they aren't a couple any more. I think it's different if one parent genuinely can't afford the basics that the children need, but beyond that, I don't think it's reasonable to expect to be subsidised.

Periperi2025 · 22/03/2026 15:56

I can see why the pair of you are divorced!

WeepingAngelInTheTardis · 22/03/2026 15:56

If hes doing 50/50 then your just being greedy. Unfortunately you’ve fucked up.

LifeOfAShowgirl13 · 22/03/2026 15:57

Oh dear, not again

Tableforjoan · 22/03/2026 15:57

I think it’s that the children are supposed to have the same style of living rather than Dior at one house and Primark at the other.

Caviar vs happy meals.

Can’t afford to the heat the house vs tropical temperatures.

But it sounds like this ex was more than willing to be paying for more than just on his time. A nice willing happy co parent. But that could all come crashing down.

Livpool · 22/03/2026 15:59

YABU - you split up so you are no longer entitled to share his money

MrsBennetsPoorNervesAreBack · 22/03/2026 16:02

Tableforjoan · 22/03/2026 15:57

I think it’s that the children are supposed to have the same style of living rather than Dior at one house and Primark at the other.

Caviar vs happy meals.

Can’t afford to the heat the house vs tropical temperatures.

But it sounds like this ex was more than willing to be paying for more than just on his time. A nice willing happy co parent. But that could all come crashing down.

I think it's reasonable to take income disparity into account if one parent is on the breadline and can't afford the basics.

Beyond that, I don't think it really matters if lifestyles differ.

GardeningMummy · 22/03/2026 16:02

sellingrocks · 22/03/2026 14:44

This went very very wrong for another poster and she pretty much lost custody of the children as they decided their mother was after their dads money and sided with him …..🤔

I don’t actually see why he should pay you a penny since you have true 50/50 split? You earn well enough - it’s not his fault he earns more than you…..

I suspect you’ve been wound up there as no judge in the land would alter custody based on a mum being “just after the dad’s money” 😆🙄

CharlieEffie · 22/03/2026 16:03

So you do 50/50 AND he offered to cover all shared costs but you refused because CMS would have given you more...that you dont need because he was already offering to pay all costs for kids...its not his fault he earns more and your not entitled too it. Which ever way the claim goes your likely to have ruined any chance of a positive co parenting relationship so i hope its worth it

amylou8 · 22/03/2026 16:03

There's something off about your post. I'm calling reverse.
Surely you don't expect him to pay when he's genuinely doing 50:50, and then come on here and be so grabby and entitled with it?

Swipe left for the next trending thread