Quick answer
This guide lists the federal deadlines most individual taxpayers should track, explains how extensions and estimated payments work, and gives practical steps to reduce penalties and interest. Where relevant, I note state variation and link to deeper guides.
Essential federal deadlines (typical calendar and rules)
- Quarterly estimated tax payments: generally due April 15, June 15, September 15, and January 15 of the following year. If a due date falls on a weekend or federal holiday, the deadline shifts to the next business day (see IRS guidance on due dates). (IRS: “Estimated Taxes”)
- Regular individual filing and payment deadline: generally April 15 (for most years). If that date falls on a weekend or holiday, the due date moves to the next business day. (IRS: “Tax Filing and Payment Due Dates”)
- Extension to file: filing Form 4868 gives an automatic extension to file (usually to October 15) but does not extend time to pay. Payments must still be made by the original filing date to avoid interest and potential penalties. (IRS: “About Form 4868”)
- State tax deadlines: states may follow the federal schedule, but some have different dates or separate extension rules. Always check your state revenue department.
Sources: IRS pages on estimated taxes and filing due dates (irs.gov), Form 4868 information page. See links in the Resources section below.
Why these deadlines matter
Missing a filing or payment deadline can create two types of cost:
1) Penalties: late-filing and late-payment penalties are calculated using IRS formulas and can add up quickly. 2) Interest: interest accrues on unpaid taxes from the original due date until payment in full (interest rates adjust quarterly). These are separate charges — paying your tax late can trigger both.
In my practice I’ve seen clients underestimate interest charges on unpaid balances; what starts as a small unpaid amount can grow materially if unpaid for months.
Common deadline scenarios and how to handle them
1) You can’t finish your return by the filing date:
- Submit Form 4868 by the regular due date to get an automatic extension to file (usually to Oct 15). This extension only delays filing, not payment. Estimate what you owe and pay electronically when you file Form 4868 or before the April due date. (IRS: Form 4868)
2) You expect to owe substantial tax next year: - Make timely quarterly estimated payments using Form 1040-ES, or increase withholding via Form W-4 to avoid estimated tax penalties.
3) Your income is irregular (gig, seasonal, commission): - Use the annualized income method or more frequent estimates. Our guide to forecasting irregular income can help: Quarterly Estimated Taxes: How to Forecast When Income Is Irregular.
Estimated tax safe-harbor rules (practical summary)
To avoid an underpayment penalty, you generally must pay either:
- At least 90% of the current year’s total tax liability, or
- 100% of the prior year’s tax liability (110% if your adjusted gross income in the prior year exceeded $150,000, or $75,000 if married filing separately).
These are the IRS safe harbors; use them when planning payments. (IRS: “Estimated Taxes”)
Tip: If you had little or no tax liability last year, safe-harbor math matters less; if your income jumps, consider paying more during the year to avoid penalties.
Typical calendar checklist (actionable items)
- January 15: Last estimated payment for the prior year due (Q4). If you file a prior-year return by Jan 31 and qualify, this date may change — verify each year. (IRS: “Tax Filing and Payment Due Dates”)
- February–March: Start gathering W-2s, 1099s, mortgage interest statements, and receipts. Order transcripts if you need prior-year data.
- April (usually Apr 15): File your return or file Form 4868 for a filing extension. Pay any tax due. Submit your first estimated payment for the tax year if applicable.
- June 15: Second estimated payment due for the tax year.
- September 15: Third estimated payment due for the tax year.
- October 15: Extended-filing deadline (if you filed Form 4868).
Note: The exact dates for a given year can shift when the standard date falls on a weekend or federal holiday (e.g., Emancipation Day historically affects April deadlines in Washington, D.C.). Always confirm current-year dates on the IRS site.
Records and how long to keep them
Keep supporting documents that substantiate income, deductions, credits, and basis for at least three years from the date you file, which is usually sufficient for refund claims or most audits. Keep records for six years if you substantially understate income, and longer for certain items (e.g., property basis). (IRS: “How long should I keep records?”)
Penalty and payment mechanics (what you’ll actually see)
- Late-filing penalty: typically a percentage of the unpaid tax per month (or part of a month), capped at a maximum. It’s charged from the original due date until the return is filed.
- Late-payment penalty: separate from the late-filing penalty; interest also accrues on unpaid amounts.
- Underpayment of estimated tax penalty: if you don’t pay enough during the year, the IRS calculates a penalty for the underpaid amounts for the period they remained unpaid. Safe-harbor rules above avoid this in many situations. (IRS: “Estimated Taxes”)
If you’re unable to pay in full, consider the IRS’s online payment options and installment agreements. Paying something by the due date reduces penalties and interest compared with paying nothing.
State deadlines and special cases
- State returns: Some states follow federal dates; others have different deadlines or separate extension filings and payment rules. Always verify your state’s due dates and extension process.
- Nonresident or part-year filers: deadlines remain the same, but where you file and how you compute tax may differ.
- Military, disaster victims, and certain overseas taxpayers: the IRS provides special relief and extended deadlines in many cases — check current IRS announcements.
Practical strategies to stay on time (tested in client work)
- Use calendar reminders: set multiple reminders weeks and days before each deadline.
- Automate payments: use electronic payments (Direct Pay, EFTPS) to ensure timely credit.
- Adjust withholding mid-year: if you expect a tax bill, increasing withholding on Form W-4 is an easy way to avoid estimated-tax logistics.
- Work with a preparer for complex situations: in my practice, clients with rental portfolios, seasonal sales, or gig income avoid penalties when we model quarterly payments early in the year.
Action plan checklist (what to do this tax season)
- Verify current-year federal due dates on the IRS website.
- Check your state tax department for state-specific deadlines.
- Estimate whether you’ll owe tax; if yes, plan either increased withholding or quarterly payments via Form 1040-ES.
- If you need more time to file, submit Form 4868 on or before the filing deadline and pay what you expect to owe.
- Keep detailed records and receipts for three to six years depending on the situation.
Helpful links and further reading
- IRS — Tax Filing and Payment Due Dates: https://www.irs.gov/businesses/small-businesses-self-employed/tax-filing-and-payment-due-dates (verify dates for the current year)
- IRS — Estimated Taxes: https://www.irs.gov/businesses/small-businesses-self-employed/estimated-taxes (safe-harbor rules and payment methods)
- IRS — About Form 4868: https://www.irs.gov/forms-pubs/about-form-4868
- Recordkeeping guidance: https://www.irs.gov/businesses/small-businesses-self-employed/recordkeeping
Internal FinHelp resources (quick links):
- Estimated Taxes — a deeper guide to quarterly payments and calculations: https://finhelp.io/glossary/estimated-taxes/
- When to File Form 4868 vs Request an Extension for State Taxes — compare federal and state extension rules: https://finhelp.io/glossary/when-to-file-form-4868-vs-request-an-extension-for-state-taxes/
- Quarterly Estimated Taxes: How to Forecast When Income Is Irregular — for gig and seasonal earners: https://finhelp.io/glossary/quarterly-estimated-taxes-how-to-forecast-when-income-is-irregular/
Common questions (short answers)
- Can I file an extension to avoid paying by April? No — extensions delay filing, not payment. You should pay what you estimate by the original due date. (IRS: Form 4868)
- What if I underpay estimated taxes? You may owe a penalty unless you meet a safe-harbor rule.
- Are U.S. citizens abroad treated differently? Many are given automatic extensions for filing, but payments often remain due on the regular date unless specific relief is granted.
Closing and disclaimer
Staying aware of deadlines saves money and stress. This guide summarizes common federal due dates and planning steps; state rules vary. For personalized tax advice tailored to your situation, consult a qualified tax professional.
Professional disclaimer: This article is educational and does not constitute individualized tax advice. Verify deadlines for the current tax year on the IRS website and consult a tax professional for decisions that affect your personal tax situation.
