Missing a single quarterly tax deadline can trigger a penalty even if you pay everything you owe by April — self-employed taxpayers are held to a different, more frequent payment schedule than W-2 employees. Here is every key date freelancers and small business owners should track in 2027.
Quarterly estimated tax deadlines
| Payment period | Typical due date |
|---|---|
| Income earned Jan 1 - Mar 31 | April 15, 2027 |
| Income earned Apr 1 - May 31 | June 15, 2027 |
| Income earned Jun 1 - Aug 31 | September 15, 2027 |
| Income earned Sep 1 - Dec 31 | January 15, 2028 |
Note that these "quarters" are not evenly spaced — the second period is only two months, and the fourth stretches across four. Dates can shift slightly if they fall on a weekend or holiday, so always confirm the exact date close to the deadline. Our quarterly estimated taxes guide covers how to calculate each payment amount.
The main filing deadline
- April 15, 2027 — Individual income tax returns (Form 1040) are generally due, along with any final balance owed for the prior tax year. This is also typically the deadline to make a prior-year SEP-IRA contribution if you haven't filed for an extension.
- October 15, 2027 — Extended filing deadline, if you filed Form 4868 for an automatic six-month extension by the April deadline.
Remember that an extension to file is not an extension to pay — any tax owed is still due by the April deadline, with interest and penalties accruing on unpaid balances even if you've properly filed for a filing extension.
Business entity deadlines, if applicable
| Entity type | Typical return deadline |
|---|---|
| S-corporation (Form 1120-S) | March 15, 2027 (extension available to Sep 15) |
| Partnership (Form 1065) | March 15, 2027 (extension available to Sep 15) |
| Sole proprietorship / single-member LLC (Schedule C) | Filed with your personal return, April 15, 2027 |
If you elected S-corp status, see our S-corp election guide for what that structure adds to your annual filing obligations.
State deadlines vary
This calendar covers federal deadlines. Many states follow the same schedule for income tax and estimated payments, but not all do, and some states have their own quarterly payment thresholds or franchise tax deadlines separate from the federal calendar. Check your specific state's department of revenue for confirmation.
Frequently asked questions
What happens if I miss a quarterly estimated payment deadline?
You may owe an underpayment penalty calculated based on how late and how large the missed payment was, even if you fully pay your balance by the April filing deadline. Paying late is generally better than not paying at all, since the penalty accrues based on the shortfall.
Do these dates change every year?
The general pattern (mid-April, mid-June, mid-September, mid-January) stays consistent, but exact dates shift slightly year to year based on weekends and holidays — always verify the current year's specific dates rather than assuming last year's calendar applies exactly.
Is there a deadline to fund a Solo 401(k) I want to use this filing season?
Generally, a Solo 401(k) needs to be opened by December 31 of the tax year it applies to, even though the actual contribution deadline can extend closer to your filing deadline — see our SEP-IRA vs. Solo 401(k) guide for the distinction.