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Iowa Business State Tax Extension I S Corporations Filing Guide

IA 1120V | Corporation Income Tax Payment Voucher 42-019  ·  S-Corporations  ·  Business Filing Guide

Overview

Iowa S Corporations are subject to state business tax filing requirements, administered by the Iowa Department of Revenue. Iowa automatically grants an extension to file with no application or form submission required.

Original Filing Deadline

The original due date for the Iowa S-Corporations return is March 16, 2026. File or remit full payment by this date to remain in good standing.

Extension Granted Automatically

Iowa automatically grants a filing extension for S-Corporations. The extended filing deadline is September 15, 2026. No application or form submission is required to receive this extension.

Payment Is Still Due by Original Deadline

The extension applies to filing only—it is not an extension to pay taxes owed. Any outstanding tax liability must be paid by the original due date of March 16, 2026 to avoid penalties and interest. Use the Iowa | Online Tax Extension Payment to pay electronically. For mail-in payments, use IA 1120V | Corporation Income Tax Payment Voucher 42-019 and send to: Iowa Department of Revenue Corporation Tax P.O. Box 10466 Des Moines, IA 50306-0466

Late Filing and Payment Penalties

• Failure to File: 10% of the tax shown due or required to be shown due.
• Failure to Pay: 5% of the tax due.

Best Practices

• Estimate and pay your Iowa business tax by March 16, 2026 to avoid interest and penalties.
• No extension form is required—Iowa grants the extension automatically.
• Use the state online payment portal for fast, convenient electronic payment.
• Set a reminder to file your completed Iowa S-Corporations return by September 15, 2026.

Final Thoughts

• Iowa’s automatic extension simplifies the process—no paperwork required. Pay any balance due by March 16, 2026 and file your return by September 15, 2026.
• Quick Reference Table
• State Abbreviation
• IA
• State Name
• Iowa
• Business Entity Type
• S-Corporations
• Extension Status
• Approved Automatically
• Return Due Date
• March 16, 2026
• Extended Due Date
• September 15, 2026
• Other Information
• Iowa grants you an automatic 6 month extension to file your business tax return. The extension is NOT an extension to pay any taxes you may have due. 90% of outstanding tax liability must be paid with Form 42-019 by original due date to avoid penalties. Iowa allows an automatic six-month extension without written request if at least 90% of the tax liability is paid by the original return due date.
• Online Payment
• Iowa | Online Tax Extension Payment
• Payment Voucher Form
• IA 1120V | Corporation Income Tax Payment Voucher 42-019
• State Payment Agency
• Iowa Department of Revenue
• Mailing Address with Payment
• Iowa Department of Revenue Corporation Tax P.O. Box 10466 Des Moines, IA 50306-0466
• Failure to File Penalties
• 10% of the tax shown due or required to be shown due.
• Failure to Pay Penalties
• 5% of the tax due.

Working with a Tax Professional

Business tax returns are complex—a licensed CPA or Enrolled Agent can maximize deductions, ensure accurate calculations, and handle filing on your behalf. Here's how working with a TaxPro typically goes:

1. 1Get matched with a verified U.S.-based CPA or Enrolled Agent
2. 2Upload your business documents via secure drag-and-drop
3. 3Review and approve your return with upfront, transparent fees
4. 4Your TaxPro files your Iowa return by September 15, 2026

Quick Reference Table

State Abbreviation	IA
State Name	Iowa
Business Entity Type	S-Corporations
Extension Status	Approved Automatically
Return Due Date	March 16, 2026
Extended Due Date	September 15, 2026
Other Information	Iowa grants you an automatic 6 month extension to file your business tax return. The extension is NOT an extension to pay any taxes you may have due. 90% of outstanding tax liability must be paid with Form 42-019 by original due date to avoid penalties. Iowa allows an automatic six-month extension without written request if at least 90% of the tax liability is paid by the original return due date.
Online Payment	Iowa | Online Tax Extension Payment
Payment Voucher Form	IA 1120V | Corporation Income Tax Payment Voucher 42-019
State Payment Agency	Iowa Department of Revenue
Mailing Address with Payment	Iowa Department of Revenue Corporation Tax P.O. Box 10466 Des Moines, IA 50306-0466
Failure to File Penalties	10% of the tax shown due or required to be shown due.
Failure to Pay Penalties	5% of the tax due.