Updated for 2026/27 · UK Child Maintenance Service
See exactly how your child maintenance is worked out
The CMS sends you a figure and no working. We show you the formula, the regulation behind it and what you can actually change. For paying and receiving parents alike.
What brings you here?
Find the information most relevant to your situation.
I'm a paying parent
Understand how payments are calculated, what income is counted, your rights around shared care, and what happens if circumstances change.
- How is my payment calculated?
- What if I have shared care?
- Can I reduce my payments?
- What happens if I can't pay?
I'm a receiving parent
Learn how to apply, how much you should receive, what to do if payments stop, and how child maintenance interacts with your benefits.
- How do I apply to the CMS?
- How much should I receive?
- What if they don't pay?
- Does maintenance affect my benefits?
Our mission is transparency
The Child Maintenance Service moves money between two households and tells neither of them how it reached the number. A letter arrives with a figure on it. The working is not shown. The rules that produced it sit in regulations almost nobody reads.
We publish the working. Every figure here is traced back to the regulation, the DWP statistic or the HMRC rule it comes from. Where the official line is disputed, we say so. Where the data does not exist, we say that too.
That includes the parts the official guidance leaves out. What the CMS earns from Collect and Pay fees. Why a company director and a sole trader on the same profit get very different bills. How much of the £791m in arrears will never be collected.
Read more about us12%, 16%, 19%
The basic rate for one, two and three or more children. Everything else adjusts these three numbers.
£791m
Unpaid child maintenance recorded as owed since 2012, about 7% of all maintenance due. DWP, March 2026.
810,000
CMS arrangements across the UK. 55% Direct Pay, 43% Collect and Pay. DWP, March 2026.
Our most popular tool
Child Maintenance Calculator
The official CMS calculator asks for gross income. Most people only know their take-home pay. Enter your salary and we'll show you the CMS figure alongside your net (after-tax) equivalent, so you know exactly where you stand.
Popular articles
The most important things to know about UK child maintenance
What Is the CMS? The Child Maintenance Service Explained
The CMS works out and collects child maintenance when parents cannot agree. What it does, what it charges, and whether you need it at all.
How Is Child Maintenance Calculated? The Full CMS Formula
12% for one child, 16% for two, 19% for three. That is the headline. The income bands, deductions and shared care rules change the real figure.
How to Reduce Child Maintenance Payments, Legitimately
Shared care nights, pension contributions and other children in your household all cut your liability. What genuinely works, and what gets challenged.
Child Maintenance Advice for Fathers: Rights and Options
Paying does not buy contact, and being refused contact does not cancel paying. What fathers are actually entitled to, and the costliest mistakes.
Don't Pay Child Maintenance? Wages, Bank Account, Then Court
The CMS can take money from your wages or your bank without going to court first. Losing your licence and prison are real, but rare. The order of escalation.
How Shared Care Cuts Child Maintenance: The Night Bands
52 nights a year cuts your payment by a seventh. 175 nights halves it and takes off another £7. Why a single extra night can be worth hundreds.
Can Child Maintenance Be Changed? Only If It Moves 25%
The CMS ignores income changes under 25% until your annual review comes round. What you must report, what gets ignored, and how to force a recalculation.
Are CMS Liability Orders Even Real Court Orders?
High Court proceedings have raised serious questions about whether CMS liability orders are valid court orders at all. What the law actually says.
Self-Employed? How the CMS Really Works Out What You Owe
The CMS uses taxable profit from your Self Assessment, which can be two years out of date. How to get that changed, and which expenses actually reduce it.
Company Director? The CMS Only Counts Your Salary
Dividends, retained profits and director's loans sit outside the standard calculation. The free variation that pulls them back in, and when it succeeds.
What DWP Told the Lords About the CMS, and What They Left Out
Senior DWP officials gave evidence on the Child Maintenance Service in March 2025. Where their account and the department's own figures do not match.
Regulation 50: Who Pays When You Share Care Equally?
When care is genuinely 50/50, one parent still pays. The rule that decides which one is not what most parents expect, and nights are counted strictly.
Parent Moved Abroad? The CMS Usually Loses All Power
The CMS cannot touch a parent living overseas, with a handful of exceptions. The REMO route, which countries enforce UK orders, and what to do if yours does not.
CMS Statistics: 1.1m Children and £791m Still Unpaid
The latest DWP figures on compliance, arrears and enforcement, and what they reveal about a system where a fifth of paying parents hand over nothing at all.
Inside the CMS: The Ageing Tech Behind Your Calculation
The systems that run child maintenance, where your HMRC data comes from, and what the technology explains about the errors parents keep reporting.
Do Pension Contributions Reduce Child Maintenance? Yes
Pensions come off your assessed income, but only automatically in some schemes. Pay into a personal pension and the CMS will not know unless you tell them.
Sole Trader vs Limited Company: Why Your CMS Bill Differs
Same profit, five times the difference in maintenance. Why directors are assessed on salary alone, and the free variation that closes the gap.
How Long Does the CMS Take? Realistic Times for Each Stage
4 to 12 weeks for a calculation, 6 to 8 for a deduction from earnings, up to 18 months for a liability order. What to do when yours overruns.
Who Actually Runs the CMS? The Names and the Chain
The CMS is not an agency. It is a directorate inside the DWP, and a named minister answers for it in Parliament. Who is accountable, and how to reach them.
Can You Go to Prison for Not Paying Child Maintenance?
The CMS can ask a court to jail you for arrears under section 40 of the Child Support Act 1991. Here is how rare it really is, and what actually happens.
Can the Other Parent Spend Child Maintenance on Themselves?
There is no legal duty to account for how child maintenance is spent, and the CMS cannot investigate it. What the law actually says, and why it was built that way.
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