Arrears are unpaid maintenance. They often build up for reasons that have nothing to do with refusing to pay: a backdated effective date, a slow decision, or a calculation that is later changed. Whichever side you are on, act early.
Why arrears appear so quickly
The effective date is usually the date the CMS first contacted the paying parent. The calculation may not be made until weeks later, so the first letter often shows money already owed. Arrears also arise when a calculation is increased after a reconsideration or appeal.
If you owe money
- Keep paying the regular amount while you challenge a decision. Arrears keep growing otherwise.
- Talk to the CMS early. Explain your situation and propose a repayment plan you can afford. Put it in writing. The arrears payment plan letter helps.
- Get free debt advice if you have other debts. See get help.
- If the calculation is wrong, challenge it. If it changes, arrears are recalculated.
Enforcement adds fees
If the CMS has to take enforcement action, fees are added to what you owe. As at October 2026 these include £50 for a deduction from earnings order or regular deduction order, £200 for a lump sum deduction order and £300 for a liability order. Collect and Pay fees of 20% also apply while you are on that service.
What the CMS can do to collect
| Action | What it means |
|---|---|
| Move to Collect and Pay | The CMS collects the money itself, with fees |
| Deduction from earnings order | Your employer takes payments from your wages |
| Deduction order from bank account | Regular or lump sum deductions from a bank or building society account |
| Liability order | A court order confirming the debt. It allows further steps. |
| Enforcement agents (bailiffs) | Can take and sell goods after a liability order |
| Charging order and order for sale | Secures the debt against property, which may be sold |
| Disqualification from driving or passport removal | For up to two years where non-payment is wilful or due to culpable neglect |
| Committal to prison | Up to six weeks, as a last resort |
Most of these need a court order and follow warnings. You will be told before serious steps are taken, and you can respond at each stage.
If you are owed money
- Check your CMS statements and keep your own record of what has been paid and when.
- If Direct Pay has broken down, ask to move to Collect and Pay.
- Ask the CMS in writing what enforcement action it is taking and when. If nothing happens, use the complaints process.
- Arrears can be collected even after a child grows up or the case closes.
Common questions
Can arrears be written off?
In limited situations the CMS can write off arrears, for example some arrears from older schemes. You can also ask whether any arrears were caused by CMS error.
I overpaid because the calculation was later reduced. Do I get it back?
Overpayments are usually set off against future payments. If the case has ended, ask the CMS how the overpayment will be dealt with, and raise it as a complaint if the CMS’s error caused it.
Sources and law
- Child Support Act 1991, sections 31 to 40B (collection and enforcement)
- Child Support (Collection and Enforcement) Regulations 1992
- Child Support Fees Regulations 2014 (SI 2014/612)
