By Michelle Uppal, a matrimonial solicitor with 25 years’ experience and a partner at Lowry Legal in London, England.
Child maintenance for self-employed parents and business owners is among the most disputed areas of family law in England and Wales — and it’s easy to see why. Crucially, there’s no payslip to reference in such cases. Income can be structured, retained within a company, or drawn in ways that might not seem to reflect a spouse’s actual wealth. And the Child Maintenance Service (CMS) doesn’t always have the tools to see the full picture themselves.
Here’s the short answer to how this really works: the CMS bases its calculations on your taxable income, as reported to HMRC. For a sole trader, that’s the net profit on your Self Assessment return. For a company director or business owner, it’s usually salary plus dividends; which may be far removed from the true value of what you control.
This guide explains exactly how the CMS calculates child maintenance for self-employed people and business owners. It explains the rules for limited company directors, when and how to challenge an assessment, and why these high net worth cases can be so complex that they often need a different approach entirely.
How Does the CMS Define Income for Self-Employed Parents?
This is not only a critical starting point, it’s also where many assessments actually go wrong. The CMS does not investigate what a parent could earn, or what their business turns over. Instead it uses gross taxable income as reported to HMRC for the most recent tax year. However, what counts as income depends on how you work. For example:
- Sole Traders and Partnerships: Net profit from your Self Assessment tax return is counted.
- Company Directors and Shareholders: Focuses on your salary plus dividends declared personally. Income retained in the company is excluded by default
- Freelancers and Contractors: Taxable income per your Self Assessment, after allowable deductions.
Allowable business expenses, so those legitimately deducted before arriving at net profit, are accepted by the CMS. That said, if expenses appear excessive, or designed to suppress income, a variation can be applied for (more on this below).
It’s important to note that the CMS uses HMRC records directly. Therefore, if your tax affairs are not up to date, the CMS may use an estimated or default figure, which can create its own problems.
How is Child Maintenance Actually Calculated?
Once income has been established, the formula used for CMS calculation is actually quite straightforward.
Standard rate (income between £200–£3,000 per week gross):
- One child: 12% of gross weekly income.
- Two children: 16% of gross weekly income.
- Three or more children: 19% of gross weekly income.
For anything below £200 per week, a reduced rate will apply. When you go above the £3,000 per week, the standard rate applies to the first £3,000, with a flat-rate addition for any income above that threshold.
The number of nights the child spends with the paying parent can reduce the liability, but it doesn’t change the underlying income figure used.
In my experience, for many self-employed parents the key issue isn’t the formula. It’s the income figure being fed into it.
Does the CMS Include Limited Company Income? What Business Owners Need to Know
The way the CMS treats income from limited companies is one of the most misunderstood areas of child maintenance law, particularly for directors and business owners with retained profits or flexible remuneration structures.
Child Maintenance Service and Limited Companies: What Income Is Counted?
If you operate through a limited company, the CMS will initially base its calculation on your declared personal income: salary, dividends, and any other income reported to HMRC. Income retained within the company, meaning profits that haven’t been drawn, is not automatically included.
This principle can be highly influential in high net worth cases. A business owner earning £500,000 in company profits but drawing a salary of £50,000 and modest dividends could receive a CMS assessment that significantly underestimates their actual financial position.
In these cases, the receiving parent could, and should, challenge this.
Director Income and the CMS Assessment
For CMS director income calculations, the starting point is what appears on the director’s personal tax return. That typically includes:
- Salary paid through the company’s payroll.
- Dividends declared and received.
- Any other personal income (rental income, investment returns, etc.).
What it may not include are retained profits, director’s loan accounts, employer pension contributions made by the company, or the value of benefits in kind.
When there’s a significant gap between a director’s lifestyle and their declared income, this is typically seen as a red flag to the other party’s solicitors and the CMS.
What if the CMS Assessment Doesn’t Reflect the Paying Parent’s Real Income?
The CMS has powers to look beyond declared income in certain circumstances. This is known as a variation.
What is an Application for Variation of a Maintenance Order?
A variation application allows either parent to ask the CMS to deviate from the standard income calculation. For self-employed and business-owning parents, the most common variation grounds are:
- Additional Income: Where the paying parent has income that is not captured by HMRC data (e.g. undeclared earnings, offshore income).
- Assets: Where the paying parent has assets worth more than £31,250 that could be generating a notional income.
- Diversion of Income: Where income is being paid into a company, trust, or to a third party — sometimes with the specific purpose of reducing the CMS liability.
Crucially, the lifestyle inconsistency principle can have a real impact here. Should a paying parent display the trappings of significant wealth while declaring a relatively modest income, the receiving parent could apply to the CMS to increase the assessed income and, with that, the overall child maintenance liability.
What Can the CMS Do?
The CMS has the power to:
- Request financial information directly from HMRC.
- Contact the paying parent’s employer or accountant.
- Carry out compliance checks if there’s reason to believe income is being hidden.
- Apply a notional income figure based on assets.
In complex cases involving companies, trusts, or overseas assets, the CMS’s investigative capacity has some limits. This is one reason why high net worth cases often benefit from a family court application running alongside, or instead of, the CMS process.
CMS Assessment vs. Court Order: Which is Better for High Earners?
The family court can make what’s known as a ‘top up order’ under the Schedule 1 Children Act 1989 order for child maintenance. This is separate from the CMS process and can be used in the following scenarios:
- The paying parent’s income exceeds the CMS cap (currently £3,000 per week gross, or around £156,000 per year).
- The CMS calculation doesn’t reflect the children’s needs or the family’s standard of living.
- There are complex financial structures that the CMS is unlikely to unpick effectively.
- Both parties want a bespoke, binding arrangement.
In high net worth divorces, a court order is often the more appropriate tool. It gives the court full visibility of the financial picture through Form E disclosure and the ability to make orders that accurately reflect the true wealth involved.
A consent order that has been agreed between the parties and approved by the court can also provide greater certainty and flexibility than a CMS assessment. These can be used to include the likes of school fees, extra-curricular activities, and other potentially valuable child-related costs.
What Should I Do If I’m Self-Employed and Facing a Child Maintenance Dispute?
The answer here depends on which side of the calculation you’re on. However, regardless of which applies, the worst thing you can do in either case is nothing.
CMS Advice for Paying Parents
The single most important thing is to make sure your financial position is transparent and defensible. That doesn’t mean disclosing more than you’re required to, it means ensuring your disclosure is accurate, consistent, and up to date.
A mismatch between your declared income and your visible lifestyle is the first thing an experienced family lawyer on the other side will look for. If that gap exists and you haven’t addressed it, you’re handing them their opening argument.
It’s also worth thinking carefully before making any changes to how you draw income from your business during proceedings. Reducing your salary or delaying dividends at this point can look like deliberate income diversion, which the CMS and the courts are both wise to. This action could lead to serious financial implications down the line.
Finally, seek legal advice before you act, not after.
CMS Advice for Receiving Parents
My first piece of advice is simply: don’t just take the initial CMS figure at face value. For self-employed parents and business owners especially, that first assessment may be based on a declared income that bears little resemblance to how the other party actually lives.
Instead, look at the full picture around your former spouse. Consider the house they live in, the cars they drive, the holidays they take. If there is a big disparity between what is on show vs what’s been disclosed, there are legal routes you can use to challenge it.
A variation application is often the starting point, but in complex cases involving companies, trusts, or significant assets, a family court application will usually give you far more leverage. The court has powers the CMS simply doesn’t, including the ability to compel full financial disclosure and to make orders that go well beyond what the CMS can award.
In either situation, specialist legal advice early in the process is a must. In my experience of high net worth cases, the difference between a poorly-managed CMS assessment and a properly-argued court order can run into tens of thousands of pounds a year.
FAQs: Child Maintenance and Self-Employment
Can the CMS force a self-employed parent to open their business accounts?
The CMS can request financial information and liaise with HMRC, but its powers to inspect business accounts directly are limited. However, in court proceedings, full financial disclosure is compulsory, so this route often gives a more complete picture.
What happens if a self-employed parent refuses to engage with the CMS?
If a paying parent fails to provide income information, the CMS can make a “default maintenance decision” based on an assumed income level. This can then be revised once accurate information is provided, but it creates a live liability in the meantime.
Can child maintenance be agreed privately without going through the CMS?
Yes, a “family-based arrangement” is an option and this can be flexible and cost-free. However, it’s not legally enforceable unless formalised through a consent order approved by the court. In HNW cases, a formalised court order is usually advisable.?
Does paying school fees count as child maintenance?
Not under the standard CMS calculation. School fees are treated separately. A court order can, however, include provisions for school fees, extras, and other specific costs, which is why high earners often prefer the court route.
How often can a CMS assessment be reviewed?
CMS assessments are reviewed annually, or when either parent reports a change in circumstances. If income changes significantly (whether up or down) an application to vary the assessment can be made at any time.
The Right Advice Means the Right Assessment
Child maintenance for self-employed parents and business owners is rarely straightforward. The CMS process was built around employees with payslips, not directors managing company profits, sole traders with unpredictable income, or high earners with complex financial structures.
Getting the right advice early can make a genuine difference to the outcome. Therefore, if you’re navigating child maintenance as a self-employed parent or business owner — on either side — Lowry Legal can help.
We’re a specialist family law firm with particular expertise in high net worth divorce and financial remedy cases across England and Wales. We understand how complex financial structures work, and we know how to get the right outcome for our clients.
To speak with one of our team, contact us today for a no-obligation chat about your situation.
This article provides general information about child maintenance for self-employed people and business owners in England and Wales. It should not be relied upon as legal advice. For guidance specific to your circumstances, consult a qualified family law solicitor.
