CMS Wrongly Closed Your Case: How to Force a Reopen

Your CMS case has just been closed without warning

You have logged into the Child Maintenance Service portal or opened a letter telling you your case is now closed. No discussion. No prior notice. The payments you were receiving have stopped, or the deductions from your wages have ended, and you have no idea why.

CMS cases get closed for reasons that look correct on paper but are wrong in reality. You can challenge this, but you have limited time to act. The mandatory reconsideration deadline is one month from the decision date. Missing it restricts your options to requesting a late review, which CMS may refuse.

Why the CMS closes cases by mistake

The CMS uses automated systems linked to HMRC data to calculate maintenance and manage cases. When that data is wrong, incomplete or outdated, closures happen. Understanding what this means in practice helps you respond effectively. These are the common triggers:

• Nil income assessment: The paying parent's PAYE data shows zero earnings for a tax year. This can happen if they moved to self-employment, had a gap between jobs, or their employer reported late. A nil assessment means no maintenance is calculated as due, so CMS closes the case.
• Address data matching: The receiving parent changes address and CMS systems match the new address, or a nearby address, to the paying parent's registered address. CMS policy treats matched addresses as evidence of cohabitation and closes the case automatically.
• Receiving parent declared ineligible: CMS records indicate the child no longer lives with the receiving parent. This typically follows a child benefit transfer to another person or a data discrepancy between government systems.
• Paying parent flagged as abroad or deceased: Data matching errors with other government databases can incorrectly flag someone as having left the UK or, in rare cases, as deceased.

None of these closures require CMS to contact you first. The system acts on data it considers reliable. When that data is wrong, this error can significantly impact you financially.

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How to challenge the closure

Your first step is mandatory reconsideration. You must request this within one month of the decision date on your closure letter. Contact CMS by phone, through your online account, or by letter. Written communication by post creates a paper trail, which can be valuable if disputes arise later about what was requested and when.

State clearly that you are requesting a mandatory reconsideration of the case closure decision. Ask them to confirm receipt in writing. Keep a record of every call: date, time, the name of the person you spoke to, and what was said.

You will need to provide evidence. For a nil income assessment that does not reflect reality, gather payslips, bank statements showing wages, or evidence of the paying parent's employment. For a wrongly matched address, provide proof of your actual address: utility bills, tenancy agreement, council tax statement. For child residency disputes, a letter from the child's school or GP confirming the address can help.

If the mandatory reconsideration fails, you can appeal to HM Courts and Tribunals Service. This must normally be done within one month of the reconsideration decision, though tribunals can accept late appeals where special reasons exist. You can request a late acceptance by explaining the circumstances that prevented you from meeting the deadline. Appeals are free. The appeal form SSCS5 and guidance are available on GOV.UK by searching "appeal a Child Maintenance Service decision" or navigating to Benefits, Building your case, Appeal a benefit decision.

There is also an internal escalation route called an SR1, or Special Request. This flags urgent or complex cases within CMS for priority handling. Ask for one if your case involves financial hardship, safeguarding concerns, or repeated administrative errors. CMS does not publicise this widely, but caseworkers can raise an SR1 if you ask directly.

If you remain dissatisfied after exhausting CMS internal processes, you can escalate to the Parliamentary and Health Service Ombudsman through your MP. The Ombudsman investigates complaints about maladministration but requires you to complete the CMS complaints process first.

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Effective dates and arrears

When a case is reopened after a wrongful closure, the effective date matters. This is the date from which maintenance calculations restart. If CMS accepts the closure was an error, the effective date should go back to when the case was wrongly closed, not when you complained.

This means arrears can accumulate. If the paying parent should have been paying throughout the closure period, those payments become owed as arrears. CMS can collect arrears through deductions from earnings, bank orders, or enforcement action.

Check the effective date carefully on any reopening decision. If it does not go back far enough, challenge it as part of your mandatory reconsideration or appeal.

Where to go for more help

GOV.UK has the formal guidance on mandatory reconsideration and appeals. For independent advice, Gingerbread offers a helpline for single parents on 0808 802 0925 and provides guidance at gingerbread.org.uk. Citizens Advice offers free advice through local bureaux or at citizensadvice.org.uk.

If you believe CMS has mishandled your personal data, you can raise a complaint with the Information Commissioner's Office. Data errors are often at the root of wrongful closures.

Act within the one month window. That deadline is strict, and missing it means relying on CMS or a tribunal to accept a late request, which is not guaranteed.

The Next Step

Now that you have read through the advice above, you might want to put it into practice. Our Child Maintenance Calculator lets you find out how much child maintenance you should pay or receive. Takes less than a minute. Try it now →