Missed deadlines are the most avoidable money wasted in tax — penalties and interest for the crime of not owning a calendar. This one is yours. Our clients also get these dates by email; subscribe free.
Individuals
| Date | What's due |
|---|
| January 15 | Q4 estimated tax payment for the prior year (Form 1040-ES) |
| April 15 | Individual returns (Form 1040) and payment · Q1 estimate · IRA/HSA contributions for prior year · extension requests (Form 4868 — extends filing, not payment) |
| June 15 | Q2 estimated tax payment · filing deadline for U.S. citizens abroad |
| September 15 | Q3 estimated tax payment |
| October 15 | Extended individual returns due — the true final deadline |
Businesses
| Date | What's due |
|---|
| January 31 | W-2s to employees and SSA · 1099-NEC to contractors and IRS · Q4 Form 941 |
| March 15 | S-corporation (1120-S) and partnership (1065) returns and K-1s — or extensions (7004) |
| April 15 | C-corporation returns (1120) and payment — calendar-year filers · corporate Q1 estimate |
| Apr 30 / Jul 31 / Oct 31 / Jan 31 | Quarterly payroll returns (Form 941) |
| September 15 | Extended S-corp and partnership returns due |
| October 15 | Extended C-corporation returns due |
Ongoing obligations
| Schedule | What's due |
|---|
| Monthly/Semi-weekly | Payroll tax deposits — your schedule depends on lookback-period liability; getting this wrong is the #1 small-business penalty (see Payroll) |
| Monthly (FL) | Florida sales & use tax returns for most filers (due the 1st, late after the 20th) |
| May 1 (FL) | Florida annual report for LLCs and corporations (Sunbiz) — miss it and the late fee is steep |
An extension extends paperwork, not payment. Tax owed is still due April 15 — file the extension and pay the estimate, and you owe neither penalty nor apology.