Child Maintenance Northern Ireland: CMS Rates, Overnight Bands, and Calculations
How CMS Calculates Child Maintenance
The Child Maintenance Service (CMS) Northern Ireland — operated by the Department for Communities — calculates weekly child maintenance using a six-step formula based on the paying parent's gross income. Private agreements between parents are always an option, but if either parent wants a statutory calculation, the CMS has sole jurisdiction.
Step 1: Gross Weekly Income
The CMS obtains the paying parent's gross annual taxable income directly from HMRC. This figure is converted to a weekly amount. The paying parent doesn't self-report their income — HMRC provides the data, so there's limited scope for understatement.
Step 2: Adjustments
Two adjustments are made before the rate is applied:
- Pension contributions are deducted from gross income
- Other children in the household trigger a percentage reduction: 11% for one child, 14% for two, 16% for three or more. These are children living full-time with the paying parent who aren't the subject of the maintenance calculation
Step 3: Which Rate Applies
The adjusted gross weekly income determines the rate:
| Weekly Income | Rate | Amount |
|---|---|---|
| Below £7 | Nil | £0 |
| £7 – £100 | Flat | £7 per week regardless of children |
| £100.01 – £199.99 | Reduced | £7 base + sliding scale |
| £200 – £800 | Basic | Percentage of income (see Step 5) |
| £800.01 – £3,000 | Basic Plus | Higher percentage on income above £800 |
| Above £3,000 | N/A | CMS can't assess income above £3,000/week — apply to court for a "top-up" order |
Step 4: Count the Children
The CMS counts how many qualifying children the paying parent is responsible for. Only children who the paying parent doesn't live with are counted — children living full-time with the paying parent are handled through the household adjustment in Step 2.
Step 5: Calculate the Weekly Amount
The basic rate percentages:
- One child: 12% of gross weekly income
- Two children: 16%
- Three or more: 19%
So a paying parent earning £500 per week gross with one qualifying child would pay £60 per week (12% × £500) before any shared care reductions.
Step 6: Shared Care Reductions
This is where the parenting schedule directly affects the calculation.
How Overnights Affect Child Maintenance
The CMS applies specific "shared care bands" based on the average number of nights per year the child stays with the paying parent:
| Overnight Stays Per Year | Band | Reduction |
|---|---|---|
| 0 – 51 nights | No shared care | No reduction |
| 52 – 103 nights | Band 1 | 1/7 reduction per child |
| 104 – 155 nights | Band 2 | 2/7 reduction per child |
| 156 – 174 nights | Band 3 | 3/7 reduction per child |
| 175+ nights | Band 4 | 50% reduction + £7/week per child |
These bands create specific financial incentives around certain custody schedules:
- Every other weekend (26 weekends = 52 nights) just hits Band 1, triggering the first reduction
- Every other weekend plus midweek overnight (78 nights) stays in Band 1
- Alternating weekends plus two midweek overnights (130 nights) reaches Band 2
- 50/50 shared care (182+ nights) falls into Band 4 — the maximum reduction
The maintenance floor is £7 per week for parents on the Basic, Basic Plus, or Reduced rates, regardless of shared care reductions. However, a Flat Rate parent (on benefits) whose child stays 52+ nights per year has their maintenance reduced to £0.
Equal Shared Care Doesn't Automatically Mean Zero Maintenance
Even at exactly 182.5 nights each per year, the CMS doesn't automatically reduce maintenance to nil. If the parent claiming maintenance can demonstrate they provide more "day-to-day care" — registered as the child's address for school and GP, paying for uniforms and activities, receiving Child Benefit — the CMS may still require some maintenance payment.
To establish full exemption under "equal day-to-day care," the paying parent must show they genuinely share all practical care responsibilities equally, not just the overnight count.
Free Download
Get the Northern Ireland — Parenting Plan Starter Checklist
Everything in this article as a printable checklist — plus action plans and reference guides you can start using today.
Direct Pay vs Collect and Pay
If the CMS calculates maintenance and both parents can cooperate, Direct Pay is the simplest option: the CMS tells you the amount, and the paying parent transfers it directly. No fees for either parent.
If the paying parent doesn't pay or the parents prefer no direct contact, the CMS can manage payments through Collect and Pay. But this comes with significant fees:
- The paying parent is charged a 20% surcharge on top of the maintenance amount
- The receiving parent has a 4% deduction taken from each payment
On a £60/week maintenance payment, Collect and Pay costs the paying parent an extra £12/week and the receiving parent loses £2.40/week. Over a year, that's £624 in surcharges and £125 in deductions — a powerful incentive to make Direct Pay work.
Maintenance and Contact Are Legally Separate
This causes more frustration than any other aspect of family law: a parent cannot withhold child maintenance because contact is being denied, and a parent cannot withhold contact because maintenance hasn't been paid. They're separate legal obligations.
If maintenance isn't paid, the CMS has enforcement powers — deduction from earnings orders, liability orders, and ultimately removal of driving licences or passports. If contact is being blocked, the remedy is a Contact Order through the family court.
Getting the Numbers Right
Your parenting schedule directly affects your child maintenance calculation, which means the schedule you agree in your parenting plan has financial consequences. The Northern Ireland Child Custody & Parenting Plan Guide includes a child maintenance estimator worksheet alongside schedule templates, so you can see exactly how different arrangements affect both contact time and support payments.
Get Your Free Northern Ireland — Parenting Plan Starter Checklist
Download the Northern Ireland — Parenting Plan Starter Checklist — a printable guide with checklists, scripts, and action plans you can start using today.