2027 Iowa Tax Deadlines
Iowa Individual income tax filing deadlines and extensions for 2027
Iowa tax deadlines are easier to manage when the filing calendar, payment rules, and extension rules sit in one place. Tax year 2027 returns are generally filed in 2028, while estimated payments run through 2027. Use the key dates below as the single source for Iowa due dates, then apply the rules by entity type.
These dates apply to calendar-year filers. Fiscal-year filers follow different due dates tied to their fiscal year and should confirm the applicable Iowa deadline before filing or paying.
Last updated: July 29, 2026
Key Iowa tax dates at a glance
This block is the single date reference for 2027 Iowa filing, payment, estimated-payment, and extension planning.
- April 30, 2027: First Iowa estimated payment for calendar-year Individuals.
- June 30, 2027: Second Iowa estimated payment.
- September 30, 2027: Third Iowa estimated payment.
- January 31, 2028: Fourth Iowa estimated payment.
- May 1, 2028: Iowa Individual, C Corporation, S Corporation, and Partnership returns and balances due for calendar-year filers.
- October 31, 2028: Extended Iowa Individual, C Corporation, S Corporation, and Partnership returns due; payment is not extended.
When are Iowa taxes due in 2027?
Iowa's 2027 calendar-year Individual, C Corporation, S Corporation, and Partnership returns are generally due May 1, 2028. Iowa estimated payments run on month-end quarterly dates, and extensions move filing only to October 2028.
When are Iowa C Corporation taxes due for 2027?
Iowa C Corporations file Form IA 1120 by May 1, 2028, and pay the expected balance by May 1, 2028. Iowa C Corporations follow the last-day-of-the-fourth-month calendar and use GovConnectIowa for supported account and payment services.
What does the Iowa C Corporation extension change?
The extended filing deadline for a calendar-year Iowa C Corporation return is October 31, 2028. The extension gives more time to file, not more time to pay, so the expected balance remains due May 1, 2028.
When are Iowa S Corporation and Partnership taxes due for 2027?
Iowa S Corporations file Form IA 1120S and Partnerships file Form IA 1065 by May 1, 2028.
What pass-through payment rules should teams watch?
Eligible Iowa S Corporations and Partnerships may elect Iowa PTET. The return, election, liability, and owner-credit reporting follow Iowa filing-year instructions and should be tracked separately from the filing extension. The projected extended filing deadline is October 31, 2028; payment and election deadlines are not automatically postponed.
When are Iowa Individual taxes due for 2027?
An Iowa Individual return using Form IA 1040 is due by May 1, 2028, and any remaining state income tax should be paid by May 1, 2028.
When is the Iowa Individual extension deadline?
The extended filing deadline for a 2027 Iowa Individual income tax return is October 31, 2028. The extension applies to filing only, so the payment deadline remains May 1, 2028.
When are Iowa estimated payments due?
Calendar-year Iowa estimated payments are due on this schedule:
- April 30, 2027.
- June 30, 2027.
- September 30, 2027.
- January 31, 2028.
Who must make Iowa estimated payments?
Taxpayers who expect an Iowa income-tax balance after withholding and credits may need estimated payments. Apply the tax-year 2027 threshold, safe-harbor, and voucher instructions when the filing-year guidance is released.
What Iowa rules should tax professionals watch for 2027?
Beyond the main due dates, Iowa has month-end filing, PTET, and GovConnectIowa mechanics worth checking before 2027 filing work begins:
Why does Iowa use month-end filing dates?
Iowa's main calendar-year returns are due on the last day of the fourth month, with the 2027 filing-year deadline rolling to May 1, 2028, because April 30, 2028, is a Sunday.
How does Iowa PTET affect pass-through work?
An Iowa PTET election can add entity-level liability, election data, payment controls, and owner-credit reporting to the S Corporation or Partnership workflow.
How should teams handle GovConnectIowa?
GovConnectIowa supports eligible filings, payments, account access, and correspondence, so tax teams should retain portal confirmations as part of deadline evidence.
Tax-professional context: Iowa return calendars, entity-level elections, owner reporting, withholding, and payment rules require a state-specific review. TY2027 forms and the final 2028 filing calendar remain subject to confirmation when the state publishes them.
Electronic filing requirements: Iowa uses GovConnectIowa for supported account management, filing, correspondence, and payment services. Use approved software for supported corporate, pass-through, and Individual returns. Use GovConnectIowa for eligible payments and account work. Review state electronic-filing mandates separately from federal requirements. Keep proof of timely electronic submission and payment with the workpapers.
Electronic account management: GovConnectIowa supports eligible filings, payments, account access, and correspondence.
What sources support these Iowa deadlines?
Iowa tax deadlines for PTET and rate changes
Iowa deadline work brings together rate changes, pass-through entity tax decisions, corporate returns, estimates, and Individual filings. Instead's AI-driven tax platform keeps the state-specific facts attached to the action list.
Use filing for Iowa returns, research for state-rule confirmation, and estimates to keep payment decisions visible before due dates. Built for tax professionals who want a better tax operation system to manage compliance and advisory work for clients.
The material discussed on this page is meant for general illustration and/or informational purposes only and is not to be construed as investment, tax, or legal advice. You must exercise your own independent professional judgment, recognizing that advice should not be based on unreasonable factual or legal assumptions or unreasonably rely upon representations of the client or others. Further, any advice you provide in connection with tax return preparation must comply in full with the requirements of IRS Circular 230.
Please note that if any due date falls on a federal or state holiday or weekend, it may be adjusted to the next business day. Always verify current deadlines with the appropriate tax professional and authorities.
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