The scenario I see constantly: A couple divorces. Husband's income is "about $250,000." Child support and maintenance are set. Then bonus season hits—Husband earns $400,000. Wife gets nothing extra.
That's a true-up failure. And it happens because most divorce agreements don't address variable income properly.
A true-up is the mechanism that reconciles what you paid against what you should have paid, based on actual income. For high-income earners with bonuses, commissions, RSUs, or business income, true-ups aren't optional—they're essential.
What Is a True-Up?
A true-up is a year-end (or quarterly) reconciliation. You compare:
- What was paid during the year based on estimated income
- What should have been paid based on actual income
The difference is paid as a lump sum—either from payor to recipient (if income was higher than expected) or credited to the payor (if income was lower).
There's no standalone "true-up statute" in Illinois. True-ups are contractual provisions built into your Marital Settlement Agreement (MSA) or divorce decree, enforced by the court.
The Basic Formula
The math is straightforward once you understand it.
Step 1: Calculate your support percentage. If your monthly net income is $10,000 and you pay $2,000/month in child support, your support percentage is 20%.
Step 2: Apply that percentage to additional income. If you earn a $50,000 bonus, you owe 20% of that bonus: $10,000.
| Component | Amount |
|---|---|
| Regular monthly net income | $10,000 |
| Monthly child support | $2,000 |
| Support percentage | 20% |
| Year-end bonus | $50,000 |
| True-up owed | $10,000 |
W-2 Employees vs. Business Owners
W-2 Employees: Straightforward
For wage earners, true-ups are relatively simple. The court uses actual W-2 income and tax data.
Key requirement: Both parties must file tax returns. W-2s alone are not enough because child support and maintenance in Illinois are determined by NET income—both parties must file their taxes at the same time.
Many decrees require: Exchange W-2s and pay stubs by February 28, file signed tax returns by mid-April, complete true-up reconciliation by June 1.
Business Owners: Complex
Self-employed and business-owner true-ups require forensic accounting.
What counts as income: K-1 distributions, profit distributions from LLCs/S-corps, fringe benefits (company car, housing, insurance paid by business), any personal expenses run through the business.
What gets "added back": Accelerated depreciation, excessive or dubious business expenses, personal perks buried in business accounts.
Under 750 ILCS 5/505(a)(3), net business income is gross receipts minus ordinary and necessary expenses—but depreciation and non-legitimate expenses don't count.
Bonuses, RSUs, and Stock Options
All compensation is included—not just salary.
Bonuses and Commissions
Bonuses are typically included in the year paid (when they hit the W-2). True-ups capture any difference between projected and actual bonus.
Stock Options and RSUs
Stock compensation counts as income when realized—not when granted. Stock options "when exercised are income," even if granted years earlier. In In re Marriage of Colangelo (2005), the court observed that even vested stock (marital property) can count as income for child support.
Retroactive Adjustments: Overpayments and Underpayments
Underpayments (Payor Owes More)
If actual income exceeded projections, the payor owes the difference. This is collected as a lump sum payment, an increase in monthly payments for the following year, or added to arrearages if not paid.
Overpayments (Payor Gets Credit)
In In re Marriage of Flynn (2021), the trial court initially refused to credit overpayments, calling them "gifts." The Appellate Court reversed: overpayments must be applied to the payor's arrearage. They are not gifts.
The Flynn rule: Any excess paid must reduce arrears or be credited against future payments.
Recent Case Law (2020-2025)
| Case | Year | Key Holding |
|---|---|---|
| In re Marriage of Solecki | 2020 | Struck MSA provision limiting business expense deductions. Statutory net income rules prevail. |
| In re Marriage of Flynn | 2021 | Overpayments are not gifts; must be credited to arrearage. |
| In re Marriage of Patel | 2025 | $500K income cap for child support was void—child support provisions cannot be non-modifiable. |
The Bottom Line
True-ups exist because income isn't static—especially for high earners. Without proper true-up provisions, bonuses, commissions, and equity compensation slip through the cracks.
The 2025 case law makes clear: courts will enforce your agreement as written, but they won't let you contract around statutory requirements. Draft carefully, document thoroughly, and reconcile annually.
Frequently Asked Questions
What Is a True-Up in Illinois Divorce? The High-Income Guide (2025)?
A true-up is a year-end reconciliation comparing what you paid in child support or maintenance against what you should have paid based on actual income. For high-income earners with bonuses, commissions, or RSUs, true-ups ensure support accurately reflects real earnings.
How does Illinois law address what is a true-up?
Illinois family law under 750 ILCS 5 governs what is a true-up. Courts consider statutory factors, case law precedent, and the best interests standard when making determinations. Each case is fact-specific and requires individualized legal analysis.
Do I need an attorney for what is a true-up?
While Illinois law allows self-representation, what is a true-up involves complex legal, financial, and procedural issues. An experienced Illinois family law attorney ensures your rights are protected, provides strategic guidance, and navigates court procedures effectively.
Written by Jonathan D. Steele
Chicago divorce attorney with cybersecurity certifications (Security+, ISC2 CC, Google Cybersecurity Professional Certificate). Illinois Super Lawyers Rising Star 2016-2025.
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