Missing a tax deadline doesn't just mean a late fee — penalties and interest compound quickly, and some missed deadlines trigger IRS notices that can escalate. Bookmark this page.
January 2026
- Jan 15 — Q4 2025 estimated tax payment due (Form 1040-ES)
- Jan 31 — W-2s must be furnished to employees; 1099-NEC due to recipients and IRS
- Jan 31 — Form 940 (FUTA) annual return due
March 2026
- Mar 15 — S-Corp (Form 1120-S) and Partnership (Form 1065) returns due
- Mar 15 — S-Corp and Partnership extension deadline (Form 7004, extends to Sept 15)
April 2026
- Apr 15 — Individual (Form 1040) and C-Corp (Form 1120) returns due
- Apr 15 — Q1 2026 estimated tax payment due
- Apr 15 — FBAR (FinCEN 114) due (auto-extended to Oct 15)
- Apr 15 — FATCA Form 8938 due with individual return
June 2026
- Jun 15 — Q2 2026 estimated tax payment due
- Jun 15 — US citizens abroad: extended filing deadline for Form 1040
September 2026
- Sept 15 — Extended S-Corp and Partnership returns due
- Sept 15 — Q3 2026 estimated tax payment due
October 2026
- Oct 15 — Extended individual and C-Corp returns due (final deadline)
- Oct 15 — Extended FBAR deadline
December 2026
- Dec 31 — Year-end tax planning actions must be completed (retirement contributions, asset purchases, etc.)
Advisory Monks Consulting tracks all deadlines for every client automatically. You'll receive reminders well in advance and never face a surprise penalty.