How much child maintenance should I pay?

How to work out how much child maintenance you pay: An example

Sometimes the easiest way to understand the formula is to see it applied. Here’s a simple, realistic scenario:

Example calculation:

1. Income: The paying parent earns £500 gross per week. This falls within the Basic rate band
2. Children: There is one qualifying child, so the rate is 12%. That works out at £60 per week (£500 × 12%)
3. Shared care: The child stays one night per week (52–103 nights a year), which reduces the figure by one-seventh, or £8.57

Final payment: £60 − £8.57 = £51.43 per week.

What if we share care equally?

If your child spends an equal amount of time living with each of you, no child maintenance is payable. Neither parent pays the other for that child.

This applies where the split is genuinely equal and clearly evidenced. Where care is close to equal but not quite, the 175+ nights reduction usually applies instead.

Understanding how care time is defined can be complex, and if you’re unsure how arrangements affect your position, it may help to read our guide on sole custody.

Is there a maximum amount of income assessed?

Yes, the CMS only assesses gross income up to £3,000 per week, which is £156,000 a year. If you earn more than this, the CMS will not require you to pay more than its maximum assessment, regardless of your actual income.

However, the receiving parent may apply to the family court for a ‘top-up’ order under Schedule 1 of the Children Act 1989, where the court can order additional maintenance above the CMS cap. These cases often involve wider financial matters and can sit alongside issues such as spousal maintenance, so getting tailored legal advice is recommended.

Ashley Le-Core, Partner at our family law office in Esher, says:

“Child maintenance on the face of it, can be a straightforward process, looking at the gross income of the non-resident parent, looking at how many children of the family there are and then also considering how many nights a week the children spend with the non-resident parent. 

“However, there can be complicating factors when the non-resident parent has a very high salary or are self-employed. The Child Maintenance Service should always be your first port of call for any dispute, but if there can be agreement between the parents as to how much should be paid, this is always preferable.”

How long do you pay child maintenance?

You pay child maintenance while your child is a qualifying child, which generally means until they reach a set age.

Payments usually continue until your child is 16, or up to the age of 20 if they remain in approved education or training. Approved education means full-time, non-advanced study, such as A-levels, rather than university.

Your relationship status doesn’t change this. Remarrying, for example, has no bearing on your obligation to keep paying for your child.

Can we arrange child maintenance between ourselves?

Yes, and in many cases it’s the simplest route. If you and the other parent can agree an amount, you can put a private arrangement in place without involving the CMS at all.

A private arrangement (sometimes called a family-based arrangement) gives you flexibility. You might use the CMS formula as a starting point and then agree extra contributions for costs like school trips or childcare on top.

If you can’t reach agreement, you can apply to the CMS who can calculate, collect, and enforce payments where needed.