Illinois Schedule SA – Specific Accounting Schedule for Fiscal-Year Filers (2026)
Last reviewed: 2025-11-07
Use the Illinois Tax Form Calculator Schedule SA: Specific Accounting Schedule (Fiscal-Year Filers) as a stand alone tax form calculator to quickly calculate specific amounts for your 2026 Illinois state tax return. Alternatively, you can use one of our Combined Federal and State Tax Estimators to quickly calculate your salary, tax, and take-home pay.
Schedule SA (Specific Accounting Schedule) is used by fiscal-year filers whose accounting period does not match the standard calendar year. Illinois requires prorated reporting of income, deductions, and credits that fall within the portion of the fiscal year overlapping the state’s tax year. This ensures only Illinois-source income earned during the appropriate period is taxed on Form IL-1040.
When to File Schedule SA
File this schedule if your fiscal year begins before and ends after December 31, or if you are required to report Illinois income for part of a nonstandard tax year. Common examples include estates, trusts, and individuals changing accounting periods.
How to Complete Schedule SA
- Enter your total income for the full fiscal year (Line 1).
- Enter income earned during the Illinois-reportable months (Line 2).
- Divide Line 2 by Line 1 to calculate the percentage of income taxable by Illinois (Line 3).
- Multiply your total adjusted gross income by this percentage (Line 4).
- Apply the Illinois rate of 4.95%. The result is your Illinois income tax for the fiscal portion (Line 5).
Attach this schedule to your Illinois return and keep detailed records of how the allocation was determined. Documentation may include accounting ledgers, contract dates, or payroll records.
| 1 | Total income for full fiscal year | |
| 2 | Income earned during Illinois-reportable months | |
| 3 | Percentage taxable by Illinois (Line 2 ÷ Line 1) | |
| 4 | Illinois taxable income (Line 1 × Line 3) | |
| 5 | Illinois tax (4.95%) × Line 4 |
Example
Example: A taxpayer operates on a fiscal year from July 1, 2024, through June 30, 2026. Total income for the fiscal year is $120,000. Of that, $60,000 was earned in 2025 (the Illinois tax year portion). Divide $60,000 by $120,000 = 0.5 (50%). Multiply $120,000 × 50% = $60,000 taxable to Illinois. Illinois tax = $60,000 × 4.95% = $2,970.
Specific Accounting Guidance
- Include only income and deductions directly tied to the Illinois-reportable months.
- Do not adjust withholding or credits unless they correspond to the same period.
- If changing from fiscal to calendar year reporting, clearly note the transition year on your IL-1040.
- Business filers using Schedule SA may also need to include corporate or partnership schedules consistent with Illinois apportionment rules.
Why Schedule SA Is Important
Specific accounting prevents duplication or omission of income across overlapping tax years. It ensures Illinois receives tax only on income earned during its active taxable period and protects taxpayers from overpayment when reporting under different accounting cycles.
Last reviewed: 2025-11-07: If you believe this form requires an update, please contact us.
Related Forms and Resources
- Form IL-1040 – Individual Income Tax Return
- Schedule NR – Nonresident and Part-Year Resident
- Schedule NR-AP – Apportionment Detail for Nonresidents
- Illinois DOR – Schedule SA Information
Quick Access Tools
Frequently Asked Questions
Do I need to file IL-1040-X if the IRS changes my income?
Yes. If the IRS adjusts your federal return and it affects Illinois tax, you must file IL-1040-X within 120 days of receiving the federal notice.
Are donations made through Schedule G-L tax-deductible?
Yes. Your Schedule G-L donations are eligible for a federal charitable deduction if you itemize on your federal Form 1040 Schedule A. Keep a copy of the filed schedule and any Lottery confirmation of your gift. The contribution will increase your Illinois payment or reduce your refund, but may lower your federal taxable income in the following year.
Changing jobs mid-year in IL
Update income/withholding and frequency; brackets are flat but credits/exemptions still matter.
Who must file Schedule FD?
You must file Schedule FD if you are a former Illinois resident who receives income (such as installment sale gains or deferred bonuses) sourced from Illinois that became taxable for federal purposes during 2026.
What documentation must accompany Schedule 1299-DA?
Attach copies of the other states’ filed tax returns, W-2s, or K-1s showing withholding and payments. Failure to attach proof can lead to denial of the credit. For convenience, you can track and upload copies directly through the MyTax Illinois portal.
Important Notes
All calculations are estimates for guidance only. Always review your return and consider professional advice when submitting official filings.