CMS Complaints, Appeals and Tribunals

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CMS Complaints, Appeals and Tribunals

When Things Go Wrong with Child Maintenance

The Child Maintenance Service (CMS) helps separated parents arrange financial support for their children. These payments can help with essential expenses, from school uniforms to household bills.

Most cases run smoothly, but problems do arise. A calculation might seem wrong, payments may not arrive, or you might feel the CMS has handled something poorly. When this happens, you have options: you can complain, ask for a mandatory reconsideration, or appeal to an independent tribunal.

Each route serves a different purpose, and knowing which one applies to your situation will save time and frustration.

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Making a Complaint

A complaint is the right step if you are unhappy with how the CMS has treated you or handled your case. This could include poor communication, unreasonable delays, staff behaviour, or administrative errors that caused problems.

Start by contacting the team that normally deals with your case. Many issues can be sorted out at this stage with a phone call or message through your online account. If the problem is straightforward, it may be resolved immediately.

When the team cannot fix things directly, your complaint will be passed to a dedicated complaints team. They aim to respond within 15 working days, though complex cases can take longer. You should receive updates throughout the process.

If you remain dissatisfied after this, you can escalate to the Independent Case Examiner. This free service reviews complaints about the CMS and certain other government agencies, but will only consider your case once the CMS's internal complaints procedure has been fully exhausted. The examiner can recommend remedies, including apologies or compensation for poor service.

You can also ask your MP to refer your case to the Parliamentary and Health Service Ombudsman once you have exhausted other routes, though this is not guaranteed to influence the outcome.

Some families also find mediation helpful for resolving ongoing disputes about child maintenance arrangements, either before or alongside formal processes.

Your situation may be slightly different. ask a question below ↓ and our editorial team will reply with our advice.

Challenging a Decision: Mandatory Reconsideration

If you believe the CMS has made an error in calculating maintenance or reached the wrong decision on your case, a complaint is not the right route. Instead, you need to request a mandatory reconsideration.

This is a formal review of the decision by a different CMS officer. You must request it within one month of receiving the decision letter. Extensions may be granted in some circumstances, but these are not guaranteed and usually require a valid reason or new evidence.

When making your request, explain clearly why you think the decision is wrong. Include any evidence that supports your position, such as payslips, bank statements, or documents showing your living arrangements. The more specific you can be, the better.

The CMS will look at the case again and send you a mandatory reconsideration notice explaining whether the original decision stands or has been changed.

Appealing to a Tribunal

If you disagree with the outcome of the mandatory reconsideration, you can appeal to the First-tier Tribunal (Social Security and Child Support). This is an independent body, separate from the CMS.

You will need to submit your appeal within one month of receiving the mandatory reconsideration notice. The tribunal will consider your case based on the evidence and the law, and you can submit new evidence that the CMS did not previously consider. The tribunal can change the CMS decision if it finds an error was made.

While appeals are free, some individuals choose to seek legal advice or hire a solicitor given the complexity of the process. Citizens Advice and other organisations can provide guidance on preparing your case.

Tribunal hearings may be held in person, by phone, or by video. In some cases, the tribunal will make a decision based on paperwork alone, without a hearing.

For current information on time limits, forms, and procedures, check GOV.UK. The rules can change, and official sources will have the most accurate details for your situation.

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ChildSupportLaws Editor 27/08/2026 at 10:00 am
@Daniel You're right that the system leans heavily on the receiving parent's word, and it's exhausting when you're unwell on top of it. For the income issue, insist on a Mandatory Reconsideration in writing within a month of each decision, then escalate to HMCTS tribunal yourself. You don't actually need your MP to do this, though they can chase delays. On shared care nights, sadly CMS treats a court order or clear written agreement as evidence, so get her email confirmation saved and resubmit.
Daniel 27/08/2026 at 9:49 am
Hi Many thanks for getting back to me, I have done this in the past but I put in change of income rather than mandatory reconsideration. Nether less my change of income should have been at least acknowledged as I was earning a lot less and they have direct access to HMRC correct. Each time they rejected my change of income. They can pick up the correct income via HMRC so can see the calculation is incorrect and they tell me this on the phone. But the battle I have to go through to get things changed is so draining and I am not a well person suffer with auto immune disease. But apparently I now need to ask my MP to raise a case to take the CSA to tribunal to get the arrears taken off. How can this be a fair process for a parent when my ex wife who raised the initial case can continue to lie about access and payments and is believed without having to provide anything. I cant get the shared care nights changed without a new court order. Even though my wife via email has agreed to the change this is not enough evidence not legally binding so continues to squeeze more money for nights she doesn't actually have the children, the whole system is broken and not fit for purpose.
ChildSupportLaws Editor 26/08/2026 at 10:00 am
@Daniel That's a genuinely awful situation and sadly a common one with CMS. Your route is to put in a formal Mandatory Reconsideration on each calculation you say is wrong, and if refused, appeal to the First-tier Tribunal (SSCS), which can actually order arrears written down where CMS used incorrect income figures. Get all the acknowledgements of error in writing, and consider a complaint to the Independent Case Examiner alongside it. Citizens Advice or a family law solicitor can help package the evidence before your financial settlement is finalised.
Daniel 26/08/2026 at 9:58 am
I have had massive problems when I have been out of work and then going back to work with CSA using an out of date tax year as their calculations and then asking me to pay xyz weekly when I get paid monthly. This results in spending weeks to get this changed to monthly and then again to the right amount. In the meantime I have incurred arrears at no fault of my own. They can't manually be removed even though the CSA have acknowledged its an error. But this has happened time and again over the last 4 years where I now have £13k of arrears which should not be there due to the system using wrong calculations, wrong payment plans and taking too long to adjust to the right figures. How do I get these arrears taken off as my ex wife is now using them against me in our financial separation agreement.
ChildSupportLaws Editor 17/05/2026 at 1:33 pm
@Another 5050 dad That "primary carer = whoever gets Child Benefit" default is the real scandal here, and CMS staff know it but their hands are tied by the regs. Take her written agreement to the tribunal, judges tend to give that proper weight even when CMS won't. Also push hard on the shared care band; day count evidence (school runs, overnights, holidays) can knock the liability down significantly or to nil. Worth requesting a Mandatory Reconsideration in writing first with all your evidence attached, as it preserves the paper trail for appeal.
Another 5050 dad 10/07/2023 at 10:00 am
£537.11 a month when I have fully shared care in every aspect. Decision made solely on the lies told by the ex and that she gets child benefit (cb charge means it would be lost from my daughter if I claimed). We agreed a family based arrangement, and she put in writing no child maintenance would be paid - but her own words were "insufficient evidence" apparently and she somehow remains the primary carer. There is no aspect of my daughter's care that we don't fully share. Well, apart from the fact that she refuses to share costs for anything I've paid for of course. Having to go to appeal, and if that fails mediation and court. They encourage us to use family based arrangements, but when the mother reneges they force fathers through the system. CMS even admitted to me on the phone that they always go with the mother's word, even though not one of their agents believed any maintenance should be paid.
Another dad treated 30/10/2022 at 6:01 pm
Another 50/50 dad checking in wondering why he is having to pay any CMS when it’s quite clear than having. 50/50 means day right day care is split equally.
Pead 29/05/2021 at 9:36 am
The csa system is a joke i was paying my ex csa even tho she had stopped me seeing my son for years then one day at work social services rang me my sin had been beaten by his stepdad who broke his collar bone according to social services this was not the 1st time and they was taking my ex to court and asked if id go in and have an interview so i travelled back jumped thru all there hoops and was told if i took my ex to court for custody they would support this which i did and on day of verdict which i may add was going my way the ex strolls in with a smile from ear to ear throws papers on the desk she had been to another court and swapped custody from her ti her mom and dad the judge demanded an enquiry over it as was not meant to be possible never heard any thing else over that but the grandmother has seen chased me for csa but only me the mother as never paid a penny how is this right or fair my son came to live with me then when he was 15 and i had him till he moved to his own place at 21 why or how is this fair im the one they constantly chasing and harassing theres got to be something i can do i support my wife and her 2 kids and pay for another directly into her bank account
Bizarre 18/05/2021 at 5:21 am
Contacted by the CMS and asked to prove that as I was made unemployed and even though I had a P45 that I had still to prove I had no employment.
Gerard 23/01/2021 at 2:55 pm
My Ex has now put me on child support after every week i give more than i am suppose to, i have been supporting my child and have been buying 90% of everything for my child, she has dumped me, fought her family physically and also stopped me completely from seeing my lovely beautiful baby...I have begged to support her in everything not only financially, but also emotionally, i have written to her the importance of a father in a child's life and all she does is send verbal abuse, I told her we will be going to court about this then. ALL of a sudden child support services has sent me a letter demanding money from me, After all money sent via BANK TRANSFER with reference to my daughter. If she goes through CMS she will get less than what she demanded, HOW STUPID. How can women treat supporting fathers like this. My ex's mother still adores how i look after my child to this current day, and i am so good with her family.
Frustrated with the 03/11/2020 at 3:53 am
I found CSA to be very helpful when I first split with my ex in 2008. They gave him a chance to pay but when he still refused 6 months later, they managed to get an attachment to earnings order set up. I had no issues and received regular payments for years. That was until CMS took over.

They decided that as his wage had increased, that he should pay more. They notified him and he said he wanted to make a direct payment as opposed to take from wages. I asked for it to come from wages because I knew he had no intention of paying. They said they had to give him a chance.

While this was going through, the CSA's attachment order was still in place. Understandably he did not want to pay any additional money until that was cancelled. CSA said they had sent the appropriate paperwork through and it should have been cancelled. CMS said they didn't have the paperwork through to cancel it. Eventually it was cancelled and CSA gave the money they collected to CMS. I was told by CSA the money was to come to me, CMS gave it to him. Over £2000. After weeks of chasing I received £800 and he was not making any regular payments.

After months of messing around, I asked CMS to deduct payment from source. They did eventually get something in place, however it was for the same amount and then they deducted their fees from it. I contacted CMS and complained. I was robbed off with 2 week investigation which found I received the correct amount. I questioned again if I should be paying his fees, was told no. Another 2 week wait and no-one got back to me. I called again and was told no I shouldn't be paying and was left in limbo again while waiting for a case handler to call me back. Then all payments stopped. I rang and again a case handler would get back to me.

Before the case handler could call me back, my daughter received a message from his sister saying tell your mother she won't be getting another penny from your dad, he's left the country. I informed CMS, who insisted they had no knowledge and would investigate. Months pass and the feedback I received was that they believed he was still in the UK. I asked for the fees I paid back and was told it should be returned and needed authorising. It never happened and I gave up trying to contact them.

Today I received my yearly statement through reminding me that my children are owed thousands of pounds and that the CMS had sent the paperwork to his address, which we know he doesn't live at anymore. I have issued a complaint through the online service but once it was submitted a message appeared stating that due to Covid 19, complaints are not being routinely looked at and someone will be in touch as and when there is time. I am frustrated and let down by the system. He is never go to pay. The best they could do is return the fees and freeze the account until he is located. They yearly reminder that we've struggled without help is seriously damaging my mental health.
Chez 10/06/2020 at 4:28 am
Covid 19 does not affect my self emoyed ex as he refuses to work whilst he dodges his support. But why dont cms chase payments he has decided to not pay and cms saying wont chase missing payments till pandemic over this coukd be months and months .he has logged numerous mandatory requests and now to tribunal to avoid paying he lives of a huge pot of money called dividrnds .eill he win the appeal .we are struggling financially .feel very let down
Chris 06/06/2020 at 5:48 pm
Cms deducted money from my isa even know i have a court hearing of appeal, that is illegal to take the money out until hearing is over?? Is this correct or can i take action for this??
unfair 20/05/2020 at 8:42 am
Can someone please explain to me how after taking my ex to court and managing to get 50/50 shared care for my daughter that I still have to pay CMS? I find this baffling as we both work she receives child benefit (which I don't), she lives with her parents whereas I have had to move city to be closer to my daughter and now have rent, council tax, bills, car finance, student loan etc etc. The only person this is truly effecting is our daughter as this means I do not have the funds to spend on her while with me. Growing up, she will clearly start to feel this and it will surely impact her feelings towards me as she will be thinking that her mum cares more and is more fun as she will be spending more on her than I would be. I will not be able to go on holidays with my daughter whereas her mum can now easily afford this. What can I do????
Si 17/04/2020 at 3:12 am
Hi I’m absolutely astonished with cms service as I split with my ex and she started claiming cms on September 2019 which was 161 a month i had struggled to pay September November and December January as had attachment of earnings that was bills my ex didn’t pay but they taken February and March from earnings at 270 so after fees I’ve paid 112 of arrears now don’t get me wrong I will pay as for kids but 4x161=644 then minus 112 arrears should be 532 but they saying I owe 795 which is just arrears to me is wrong and absolutely disgusting as I have 50/50 custody now how on earth do they think 263 pound is not going to be noticed
Deb 20/09/2019 at 10:18 pm
My partner split from his ex jan 2017 he walked out of their home and she moved her new partner in 3 days later. She had all his accounts and went on cms website and input what she thought was his net figure which actually was his gross but could not check it as she had the figures. He paid her £520 a month voluntarily when he met me I said that seemed a lot. His accounts were not up to date due to her having everything so they went off last fig of Hmrc. It was £163 a month. Then it got put to a financial investigator because of his income which we updated and provided he was happy and passed it back to cms to work out. It took them 2 months to come back with a figure of £140 a month which included some arrears but not sure what. Get a text in July next 3 payments will be £499 a month! Ring up say it’s arrears. We challenged it as he had already overpaid her nearly £7 k voluntarily. They rang and said if you don’t hear from us by 1st of month pay normal fee ie not with arrears on. We did this, went on holiday. Came back to a letter saying we have 7 days to provide evidence of not paying arrears which had passed . Rang up said could we have extra time to send in. He said he would try. Next day received a letter because he missed £23 payment which he was told not to pay he’s not on Collect and pay or provide evidence why. Wrote letter saying what they said and said we would pay it but not going to collect and pay. 2 days later received letter looked into complaint and sticking to £1k arrears so not even got our evidence. Next letter we have collect and pay arrears even though not replied to our letter and arrears gone up to £1400 even though we have not missed payments. Received next letters for annual review £200 including any arrears so where has £1400 gone but another letter saying still owe it. Spoke to them today apparently arrears gone up as receiver saying we missed a payment when it clearly shows it coming out of his account. It’s a farse and causes so much stress !!!
Angry mam 19/09/2019 at 9:53 pm
I knew my ex was receiving universal credits I informed cms of this and they said they had no record of this I then put in a complaint as I saw msgs on phone to log onto his Uc account therefore I started to receive a big £7 a week my ex then started to work around one Yr later I informed cms of this and his employers address for over a mth I rang cms to check progress I just kept getting told they are trying to contact his employer the employer has two weeks to respond if they don't respond by two weeks will try to contact again. I asked the cms can they not get details of earnings from hmrc and they informed no I then put on another complaint then all of a sudden a week later I received notice of my new award of a whole & 7 a week as they worked out his earnings as £70 per week I know this is not correct I have now put in a mandatory reconsideration and will appeal that if have to as I know earnings are over £200 a week I feel the cms have not done job and just get fobbed off and lied to I asked how they got his earnings and last lady said by hmrc but previously said they don't contact hmrc shall I also put in another complaint as well as mandatory reconsideration I spent dlso much time ringing sending msgs waiting half an hr to answer phone when I could be spending time with chikdren if they just did job in first place
Feel lost 12/07/2019 at 12:52 pm
My partners ex decided to start claiming after years of being happy with the payment for nearly £400 a month CSA came to us with a figure they apparently got from HMRC (this is a lie and have letters from HMRC saying it’s incorrect) but this is amount is nearly £10,000 more then his p60 and £20,000 more then his basic wage which means they want nearly £200 more a month which will cripple us we physically can’t afford it with 3 of our own children and a house and bills we’re having to appeal as they said they won’t look at a it again as it’s not 25% but surly they would need to get the figure right in the first place? How can they just make one up? We can’t be the only people this is happening to I feel completely lost and just hoping by appealing a judge will see our side :(
SS 10/05/2019 at 10:11 pm
I was informed by CMS in January 2018 that my ex husband was working, despite me only receiving the flat rate (£2.50pw per child). It took until the end of August 2018 to get a proper payment, despite being strung along for months by the CMS and being promised payments. By the time I got a payment £2000 of arrears had accumulated. There is now a deduction of earnings order in place.
Since August payments have been eratic and varied and in 3 separate months I haven’t received a payment at all.
When chasing the payments the CMS have been continually unhelpful, obstructive and provided inconsistent information.
However it appears that on the months I haven’t received a payment the CMS have withheld my payments despite receiving them from the employer. It appears that the employer pays a bulk payment to the CMS each month as he has several employees who have deduction of earning orders. If there is an issue with any of the payments that is paid in the bulk payment they won’t realise anyone’s payment until it is sorted. So my payments have been withheld for long periods of time because there is an issue with a payment on another case that is totally unrelated to my case. I am currently pursuing another complaint and I have informed my MP about this ongoing issue. The CMS are currently withholding a payment they received from the employer nearly 4 weeks ago and they won’t explain why or release my payment.
It’s a joke!!!!
EileenH82 10/04/2019 at 2:26 pm
Since January 2019 I asked Cms to open a case against my daughters adoptive father
After a few days of confirming with their legal team about whether or not they can pursue a claim they contacted me with their decision. Not long after that they sent me a calculation of what I will be receiving from then on I have received nothing. The adoptive parent requested a mandatory reconsideration a week before the first payment was due. This was on the 5th of March that I got the news but they told me he should still pay until they complete their investigation. He has not paid and another payment has gone unpaid and cms still tell me they're waiting on more evidence to come in. He is getting away with not paying and cms are happy to take their time with my case. 2 months of them doing a mandatory reconsideration is a joke as his wage is not different so what can I do to get my money?
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