Illinois uses an income-shares framework, but the inputs can be the real litigation issue. Business income, bonuses, equity compensation, voluntary underemployment, health-insurance costs and parenting schedules can all affect the analysis.
Define income correctly
Base salary is not always the whole income picture. Bonuses, commissions, business distributions, recurring benefits and other compensation may require analysis under the statute.
High income is not merely arithmetic
In higher-income matters, the statutory framework and the children’s circumstances can require a more contextual analysis than a simple online-calculator result.
Modification requires the right standard
Private modification cases generally require a substantial change in circumstances. The statutory 20% inconsistency route is limited to specified HFS-enforcement circumstances and should not be generalized to every case.
Questions that change the analysis.
Can bonuses and variable compensation count as income?
They can. Illinois starts with a broad definition of income, subject to exclusions and adjustments. A base salary alone can understate compensation. Business gross receipts are not the same as personal support income: ordinary and necessary operating expenses and certain business-paid benefits require analysis. Bring the compensation history, tax records and business financials so recurring earnings and unusual transactions can be distinguished.
Source: 750 ILCS 5/505(a)(3) and (3.1); 750 ILCS 5/504(b-3).
Can a court impute income?
Yes, when the statutory requirements are met. For voluntary unemployment or underemployment, the court determines potential income from the parent’s circumstances and the local job market. A former salary is not automatically the correct amount. Imputation requires an evidentiary hearing or the parties’ agreement, with specific written findings identifying its basis.
Source: 750 ILCS 5/505(a)(3.2a)–(3.2b).
Can child support be changed if income rises substantially?
Yes. A substantial income increase can support a request to modify child support, but does not automatically change the existing order. The court examines the financial circumstances, the children’s needs and the statutory factors, including the standard of living they would have enjoyed without the divorce. A request generally affects only installments accruing after due notice of the filed motion. The separate 20% guideline-inconsistency route has additional conditions and is limited to specified HFS-enforcement cases after at least 36 months; it is not a universal 20% income-change rule.
Source: 750 ILCS 5/510(a).
Child support when income changes month to month
A paycheck, a tax return and income for child support are not necessarily the same number. Start with each source of earnings, the period it covers and whether it is recurring. Then apply Illinois’s income rules and the appropriate adjustments. The gross-income child support calculator gives a basic wage-income estimate; disputed or business-derived income needs a fuller analysis.
Bonuses, commissions and equity compensation
Collect the compensation plan, payment history, current year-to-date records and any explanation of a one-time payment. A single unusually good or bad month may give an incomplete picture. Separate the date a bonus was earned from the date it was paid and identify whether taxes or other deductions were already reflected in the number provided.
For example, a hypothetical $120,000 salary plus a $30,000 annual bonus is different from twelve months of $10,000 salary alone. Show both components and the bonus history. That arithmetic organizes the evidence; it does not decide whether every payment should receive identical legal treatment. For stock compensation, also retain grant, vesting and sale records. See RSUs and stock options.
Business receipts are not personal wages
750 ILCS 5/505(a)(3.1) addresses business income after ordinary and necessary operating expenses, with exclusions for accelerated depreciation and inappropriate or excessive expenses. Significant business-paid benefits that reduce personal expenses can also matter. A tax deduction or owner’s draw does not, by itself, settle the support analysis.
Bring business returns, profit-and-loss statements, balance sheets, owner compensation and distribution records, and an explanation of personal expenses paid by the company. Match the same time periods. Avoid counting the same cash twice as both business income and a distribution. Counsel may need accounting assistance to reconcile the documents. See business-owner divorce.
A job change is a fact to document
Keep the termination notice, new offer, benefit information, job-search records and current pay documents. If a parent claims reduced earning capacity, evidence about health, experience, available work and actual efforts matters. Section 505 addresses potential income and requires an evidentiary hearing or agreement, with specific findings, for imputation.
An online estimate does not amend an existing order. Before changing payments, have counsel review the current order and the requirements of Section 510. Explain when the change occurred, what is temporary, what is documented and whether a motion is already pending.
Questions worth resolving before discussing a number
- Does the income figure include the full year’s bonus or only base pay?
- Are business expenses supported, and do they reduce personal living costs?
- Is maintenance being paid or received, and how is it treated for tax purposes?
- Are there other support obligations, benefit credits or unusual tax circumstances?
- Do the children share one schedule, and what parenting time is actually exercised?
- Which insurance, childcare and other expenses are separate from basic support?
The Illinois HFS schedules and worksheets provide the calculation framework. The quality of the inputs still matters. Charles can coordinate the legal and financial review through a team tailored to your matter at Beermann.