January Tax Deadlines for US Small Business in 2026
All important January 2026 tax deadlines for sole proprietors, LLCs, S-Corps, and C-Corps. Don't miss a filing.
Tax deadlines are easy to miss — and expensive. Here's every major federal tax deadline in January 2026 that affects US small businesses.
Quick overview
- January 15 — Q4 estimated tax payment due (2025 tax year)
- January 31 — W-2 forms to employees and SSA
- January 31 — 1099-NEC forms to contractors and IRS
- January 31 — Form 940 (federal unemployment) annual filing
- January 31 — Form 941 (Q4 payroll tax) filing deadline
Detail on each deadline
January 15: Q4 estimated tax payment due (2025 tax year)
Missing this deadline usually triggers a penalty of 5% per month (capped at 25%) plus interest. File even if you can't pay — the failure-to-file penalty is 10x the failure-to-pay penalty.
January 31: W-2 forms to employees and SSA
Missing this deadline usually triggers a penalty of 5% per month (capped at 25%) plus interest. File even if you can't pay — the failure-to-file penalty is 10x the failure-to-pay penalty.
January 31: 1099-NEC forms to contractors and IRS
Missing this deadline usually triggers a penalty of 5% per month (capped at 25%) plus interest. File even if you can't pay — the failure-to-file penalty is 10x the failure-to-pay penalty.
January 31: Form 940 (federal unemployment) annual filing
Missing this deadline usually triggers a penalty of 5% per month (capped at 25%) plus interest. File even if you can't pay — the failure-to-file penalty is 10x the failure-to-pay penalty.
January 31: Form 941 (Q4 payroll tax) filing deadline
Missing this deadline usually triggers a penalty of 5% per month (capped at 25%) plus interest. File even if you can't pay — the failure-to-file penalty is 10x the failure-to-pay penalty.
Not sure which deadlines apply to you?
It depends on your entity type:
- Sole proprietor / single-member LLC: file Schedule C with Form 1040 by April 15
- Multi-member LLC / partnership: Form 1065 by March 15
- S-Corp: Form 1120-S by March 15
- C-Corp: Form 1120 by April 15 (or 15th of 4th month after fiscal year-end)
- Employer: Form 941 quarterly, W-2/1099 annually
How TinSuite helps you stay on top
- Deadline calendar built into your dashboard
- Email and in-app reminders 7 and 1 day before each deadline
- Pre-filled forms generated from your books — just review and file
- Multi-state aware — adds state deadlines based on your nexus