Use this path when you disagree with a CMS decision — the amount, shared care band,
income period, or arrears figure. Service complaints are a separate route
(Guides → Complaints & ICE).
Deadlines are short. Diarise them the day a letter arrives. Late applications can sometimes
be accepted — explain the delay in writing and keep proof of posting or online submission.
Which stage are you at?
I just got a decision letter
Start with a written calculation breakdown, then MR within usually 30 days.
I already asked for a breakdown
If the figure is still wrong, request mandatory reconsideration with evidence.
I have an MR notice and still disagree
Appeal to the Social Security and Child Support Tribunal (SSCS2), usually within one month.
Enforcement started during the dispute
Keep the dispute going and follow the enforcement guide in parallel.
1) Ask for a written explanation
Note the income figure, tax year/period, rate band, and shared care nights on the letter.