How to challenge a Child Maintenance Service decision
If you think CMS has made the wrong decision, the most effective starting point is to identify exactly what was decided, why you say it is wrong and which evidence or legal point supports your position.
Build an MR request1. Read the decision letter carefully
Separate a decision dispute from a service complaint. A complaint may deal with delay, communication or handling. A challenge deals with whether the actual CMS decision is correct.
2. Gather evidence for the specific issue
For shared-care disputes this may include care records and practical responsibility. For income disputes it may include payslips, HMRC information or evidence relevant to a variation. For arrears disputes, payment records and CMS correspondence can be important.
3. Request mandatory reconsideration where required
Mandatory reconsideration asks CMS to look at the decision again. GOV.UK says this is normally requested within 30 days of the date on the decision letter. Your own decision letter is the key document for the applicable route.
4. Appeal if the dispute is not resolved
After the mandatory reconsideration notice, an appeal may be available to the Social Security and Child Support Tribunal. The tribunal is independent of CMS and DWP. Further appeal to the Upper Tribunal is generally concerned with errors of law rather than simply re-running the facts.
Keep the argument focused
Strong challenges usually make it easy to see the decision being disputed, the specific error alleged, the evidence relied on and the outcome requested. Keep a dated copy of what you submit.
Official information: GOV.UK CMS complaints and appeals.