Every deadline. Every year.
Every penalty if you miss it.
Federal filing deadlines, quarterly estimated payments, payroll, sales tax, and entity-specific due dates — with IRS penalty details for every date.
January 2026
2 deadlinesFebruary 2026
1 deadlineMarch 2026
5 deadlinesDelaware Franchise Tax — March 1
Delaware corporation annual franchise tax report due March 1, 2026 — applies to all DE-incorporated entities.
S-Corp Election Deadline — March 15
S-Corp election (Form 2553) deadline for calendar-year entities wanting S-Corp treatment for 2026 tax year.
S-Corp Return Deadline — March 17
S-Corporation Form 1120-S due March 17, 2026 — shareholder K-1s must be issued by this date.
Partnership Return Deadline — March 17
Partnership Form 1065 due March 17, 2026 — K-1s to all partners by this date.
ACA 1095-B/C IRS Filing Deadline — March 31
ACA employer mandate information return (Form 1095-C) IRS filing deadline — March 31, 2026.
April 2026
10 deadlinesQ1 2026 Estimated Tax — April 15
First quarter 2026 estimated tax payment due April 15 — covering January 1 through March 31 income.
Individual Tax Return Deadline — April 15
Federal individual income tax return due April 15, 2026 for tax year 2025.
C-Corp Return Deadline — April 15
C-Corporation Form 1120 due April 15, 2026 for fiscal year ending December 31, 2025.
IRA / Roth IRA Contribution Deadline — April 15
Traditional IRA and Roth IRA contribution deadline for 2025 tax year — April 15, 2026. SEP-IRA deadline extended if you file an extension.
FBAR Filing Deadline — April 15 (Auto-Extended to October)
FBAR (FinCEN Form 114) due April 15 with automatic extension to October 15 — required for foreign accounts exceeding $10,000.
Gift Tax Return (709) — April 15
Form 709 federal gift tax return due April 15, 2026 for gifts made during 2025.
California Estimated Tax — Q1 April 15
California estimated income tax Q1 payment due April 15, 2026 — CA uses a 30/40/0/30 installment schedule.
New York State Estimated Tax — Q1 April 15
New York State estimated income tax Q1 payment due April 15, 2026.
Form 941 Quarterly Payroll — Q1 April 30
Form 941 quarterly payroll tax return due April 30, 2026 (Q1) — subsequent quarters due July 31, October 31, and January 31.
State Sales Tax — Quarterly Overview
State sales tax quarterly filing overview — due dates and nexus rules vary by state. April 30, July 31, October 31, and January 31 are the most common.
June 2026
1 deadlineSeptember 2026
1 deadlineOctober 2026
3 deadlinesIndividual Extension Deadline — October 15
Final extended deadline to file your 2025 individual federal tax return — October 15, 2026.
C-Corp Extended Deadline — October 15
Final extended deadline for C-Corporation Form 1120 — October 15, 2026.
SEP-IRA Contribution Deadline (Extended) — October 15
Final deadline to contribute to a SEP-IRA for 2025 if you extended your return — October 15, 2026.
Deadlines are only half the picture.
A licensed TaxosAgent professional reviews your situation before every deadline — so you never just file to file. You file to win.
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