2026 Tax Deadline Calendar for S-Corporations
All IRS due dates for S-Corporations in 2026, including Form 1120-S filing, K-1 distribution, estimated tax payments, and W-2/1099 deadlines.
S-Corporations file Form 1120-S and issue Schedule K-1 to each shareholder. The corporate return is due March 16, one month earlier than individual returns. Shareholders then report K-1 income on their personal Form 1040. The S-Corp itself generally does not pay income tax.
Showing 10 deadlines for S-Corporation
Next Deadline
1099 Forms Due (Paper Filing)
6 days
Feb 28
January 2026
Q4 2025 Estimated Tax Payment Due
PaymentFinal quarterly estimated tax payment for 2025
W-2 and 1099-NEC Filing Deadline
InformationEmployers must send W-2s to employees and file with SSA. 1099-NECs due to contractors and IRS.
February 2026
1099 Forms Due (Paper Filing)
InformationPaper-filed 1099-MISC, 1099-INT, 1099-DIV due to IRS (electronic deadline is March 31)
March 2026
S-Corp & Partnership Tax Returns Due
FilingForm 1120-S for S-Corps and Form 1065 for Partnerships. Issue K-1s to shareholders/partners.
S-Corp/Partnership Extension Deadline
ExtensionFile Form 7004 to request 6-month extension (moves deadline to September 15)
1099 Forms Due (Electronic Filing)
InformationElectronically-filed 1099-MISC, 1099-INT, 1099-DIV due to IRS
April 2026
Q1 2026 Estimated Tax Payment Due
PaymentFirst quarterly estimated tax payment for 2026
June 2026
Q2 2026 Estimated Tax Payment Due
PaymentSecond quarterly estimated tax payment for 2026
September 2026
Q3 2026 Estimated Tax Payment Due
PaymentThird quarterly estimated tax payment for 2026
Extended S-Corp & Partnership Returns Due
FilingExtended Form 1120-S and Form 1065 returns due
Key Tax Tips for S-Corporations
Earlier Filing Deadline
S-Corp returns (Form 1120-S) are due March 16 — one month before individual returns. K-1s must be issued to shareholders by this date so they can file their personal returns.
Reasonable Salary Requirement
S-Corp owner-employees must pay themselves a reasonable salary subject to payroll taxes. The IRS scrutinizes salaries that are too low relative to distributions.
Pass-Through Estimated Payments
The S-Corp itself does not make estimated payments. Instead, shareholders make quarterly estimated payments on their personal returns based on their K-1 income share.
2026 Quarterly Estimated Tax Schedule
| Quarter | Income Period | Payment Due |
|---|---|---|
| Q4 2025 | Sep 1 - Dec 31, 2025 | January 15, 2026 |
| Q1 2026 | Jan 1 - Mar 31, 2026 | April 15, 2026 |
| Q2 2026 | Apr 1 - May 31, 2026 | June 15, 2026 |
| Q3 2026 | Jun 1 - Aug 31, 2026 | September 15, 2026 |
| Q4 2026 | Sep 1 - Dec 31, 2026 | January 15, 2027 |
S-Corporation Tax Deadline FAQs
When is the S-Corp tax return due in 2026?
Form 1120-S is due March 16, 2026 for the 2025 tax year. This is one month before individual returns. You can file Form 7004 for a 6-month extension, moving the deadline to September 15, 2026. K-1 forms must be issued to shareholders by the filing deadline.
Do S-Corps make quarterly estimated tax payments?
The S-Corp entity generally does not make estimated payments. However, shareholders must make quarterly estimated payments on their personal returns for their share of S-Corp income. Payment dates are January 15, April 15, June 15, and September 15.
What is the K-1 deadline for S-Corps?
Schedule K-1 forms must be provided to shareholders by the Form 1120-S filing deadline: March 16, 2026. If the S-Corp files an extension, K-1s should still be issued as soon as possible so shareholders can file their personal returns.
What happens if an S-Corp misses the March 16 deadline?
The IRS charges a late filing penalty of $235 per shareholder per month (or fraction of a month) the return is late, up to 12 months. For an S-Corp with 3 shareholders, that is $705 per month. File Form 7004 before March 16 to get an automatic extension.
What payroll deadlines apply to S-Corps?
S-Corps must file W-2 forms for employees and owner-employees by January 31. 1099-NEC forms for contractors are also due January 31. Payroll tax deposits (Forms 941) are due quarterly. Annual federal unemployment tax (Form 940) is due January 31.
Official IRS References
- IRS Publication 509: Tax Calendars
Official IRS calendar of tax deadlines
- IRS Estimated Taxes Guide
Information on quarterly estimated tax payments
- IRS: When to File
Filing deadlines and extension information
Deadlines may change due to holidays, weekends, or IRS announcements. Always verify current deadlines on IRS.gov.