Federal deadlines for calendar-year filers. Any date that lands on a weekend or legal holiday moves to the next business day. States run on their own calendars.
Pass-through entities file first. Everyone else follows a month later.
The payment periods aren't even quarters. Two of them are shorter than three months, which is where people get caught short.
If you have employees, contractors, or an S-corp election on the horizon, these matter as much as the annual return.
An extension is automatic if you file it on time. It's also widely misunderstood.
The dates above are the simple part. These are what actually generate the notices.
Own due dates, own extension forms, own estimate schedules. Some states require a separate extension even when the federal one is automatic.
Nothing above applies by date. Pass-throughs file the 15th day of the third month after year end; individuals and C-corps, the fourth.
The failure-to-file penalty on a 1065 or 1120-S is assessed per owner, per month. A late return with zero tax due still gets expensive.
Chasing contractor information in January is the reason 1099s go out late. Get the W-9 before the first check clears, not after year end.
A calendar keeps you compliant. It doesn't tell you what you'll owe or whether your structure still fits. That's what the playbooks are for.
This overview is general educational information, not tax, legal, or accounting advice, and it does not create a professional relationship. Dates shown are federal deadlines for calendar-year filers and shift for weekends, legal holidays, disaster relief, and fiscal-year elections. Confirm your own deadlines with a qualified tax professional.
Turn tax and financial planning into a year-round system with practical insights, tools, reminders, and guided workflows.
Free to join. Built to help you take control.
