42-001: IA 1120 Iowa Corporation Income Tax Return 42-001 (2024)
Iowa · Iowa DOR · Used for tax years 2024
The 2024 IA 1120 is the Iowa Corporation Income Tax Return. It reports federal taxable income, Iowa income adjustments and apportionment, tax, credits, payments, and any balance due or overpayment.
What you'll need
Include a complete copy of your federal return as filed with the Internal Revenue Service.
For federal consolidated filers, include:
- Pages 1–5 of the consolidated federal return.
- Consolidating income statements.
- Federal Form 851 for filing status 3.
- Iowa Schedule H and any other forms related to the Iowa return.
Other attachments depend on the entries you make:
- IA 2220 for the estimated tax underpayment penalty.
- IA 1139-CAP for a capital loss carryback on an amended return.
- IA 4136 for the fuel credit.
- IA 148 for nonrefundable credits and refundable credits other than the fuel credit.
- Schedule CC for composite and PTET credits.
- A statement for other payments on Schedule C2.
- Supporting schedules for “Other” additions or reductions on Schedule A, and partnership gross receipts or “Other” receipts on Schedule E.
- A schedule showing the computation if you annualize the tax.
The form also uses amounts from IA 4562A, IA 163, IA 101, Iowa K-1s, and Schedule D where applicable.
How to file
You may e-file the return or mail it to:
Corporation Tax Return Processing
Iowa Department of Revenue
PO Box 10468
Des Moines, IA 50306-0468
Complete the corporation information, filing status, income, tax, credits, and payment sections. Include the required federal return copy and applicable supporting forms and schedules.
Sign by hand or use a digital signature with a digital certificate. Stamped or typed signatures are not accepted.
If you owe a balance, pay electronically or submit payment with a voucher.
Forms and schedules are available at revenue.iowa.gov.
Common mistakes
- Do not enter an amount below $0 on line 13, income subject to tax.
- Do not include the estimated tax credit on line 15. Schedule C2 lists the credit from the prior period and estimated tax payments.
- Do not use a stamped or typed signature. Sign by hand or use a digital signature with a digital certificate.
- Do not omit the required federal return copy or the additional federal consolidated filer attachments.
- If you annualize the tax, include a schedule showing the computation.
- Follow Schedule E's rounding instruction: round the ratio to six decimal places and enter it as a percentage. The printed example converts 0.1234505 to 12.3451%.
Questions people ask
What tax rates does the 2024 form use?
If line 13 is $100,000 or less, multiply it by 5.5%. If it is over $100,000, multiply it by 7.1% and subtract $1,600.
Can I apply an overpayment to the next tax period?
Yes. Line 25 lets you credit an overpayment to the next period's estimated tax. Line 26 is the refund requested, calculated by subtracting line 25 from line 24.
Can someone else discuss this return with the Department?
The form has a Third Party Disclosure Designee section where you can indicate whether you want to allow an individual to discuss the return with the Department and provide that person's contact information.
Where can I ask questions about the return?
The form lists 515-281-3114 and 800-367-3388 for questions, and idr@iowa.gov for email.