The main tax important date you need to know

Federal income tax is due on April 15 of the year after you earn the income. That is the important date to file your return and pay any tax you owe. If April 15 falls on a weekend or holiday, the important date moves to the next business day. State income tax important date vary by state — most follow the federal date, but a few differ by a week or more.

You do not have to wait until April 15 to pay. If you expect to owe tax when you file, you can pay throughout the year through estimated quarterly taxes, or your employer can withhold more from each paycheck. The IRS also accepts payments year-round through its website, by phone, or by mail.

Missing the April 15 important date costs you. The IRS charges a failure-to-file penalty (usually 5% of unpaid tax per month, up to 25%) and a failure-to-pay penalty (0.5% per month). Interest accrues daily on any unpaid balance. If you cannot pay by April 15, filing your return on time and paying what you can reduces the penalties.

Key Takeaways

  • Federal income tax returns are due April 15 each year, and most states follow the same date.
  • If you owe tax, you can pay in full by April 15 or spread payments through the year using estimated quarterly taxes or paycheck withholding.
  • Penalties for late filing (5% per month) are steeper than penalties for late payment (0.5% per month), so file on time even if you cannot pay in full.
  • You can request a six-month extension to file, but it does not extend the time to pay — tax is still due April 15.
  • Self-employed people and those with investment income often owe estimated quarterly taxes on a different schedule than W-2 employees.

Estimated quarterly taxes for self-employed and side-income earners

If you are self-employed, a contractor, or earn significant investment income, you likely owe estimated quarterly taxes four times a year instead of waiting until April 15. The IRS requires this because you do not have an employer withholding tax from your paychecks.

The four payment dates are April 15, June 15, September 15, and January 15 of the following year. Each payment covers the income you earned in roughly a three-month period. You calculate your estimated tax using Form 1040-ES, which walks you through the math based on your expected income and deductions for the year.

If you miss a quarterly important date, you owe a penalty on that quarter's underpayment, even if you pay everything by April 15. The penalty is small if you catch up quickly, but it adds up if you skip multiple quarters. Many self-employed people set aside money each month and pay it all at once on the due date, or use tax software that calculates the quarterly amount for them.

What happens if you file late or pay late

Filing late and paying late trigger different penalties. The failure-to-file penalty is steeper — it starts at 5% of your unpaid tax for each month you are late, capped at 25%. The failure-to-pay penalty is 0.5% per month, also capped at 25%. If you owe both, they can overlap, but the combined penalty does not exceed 47.5%.

On top of penalties, the IRS charges interest on any unpaid tax. The interest rate changes quarterly and is currently around 8% per year, compounded daily. Interest accrues whether you file on time or not, so the longer you wait to pay, the more interest you owe.

If you cannot pay by April 15, file your return anyway. Filing on time stops the failure-to-file penalty from growing, even though you still owe the failure-to-pay penalty and interest on the unpaid balance. You can then set up a payment plan with the IRS, request a short-term extension to pay, or explore other options.

Filing extensions and payment plans

You can request a six-month extension to file your return using Form 4868. This pushes your filing important date from April 15 to October 15. However, the extension does not extend the time to pay — tax is still due April 15. If you do not pay by April 15, you owe failure-to-pay penalties and interest on the unpaid amount, even though you have until October 15 to file.

If you cannot pay the full amount by April 15, the IRS offers payment plans. A short-term plan (120 days or fewer) has no setup fee. A long-term installment agreement costs $31 to $225 depending on how you set it up and how much you owe. You can request a plan online through the IRS website, by phone, or by mail with your return.

Payment plans do not stop penalties and interest, but they prevent the IRS from taking collection action (like wage garnishment or bank levy) as long as you make your payments on time. If you fall behind on the plan, the IRS can resume collection action.

Paycheck withholding and how it affects your due date

If you are a W-2 employee, your employer withholds federal income tax from each paycheck. That withholding is credited toward your April 15 tax bill. If your employer withholds too much, you get a refund when you file. If your employer withholds too little, you owe the difference by April 15.

You control how much your employer withholds by filling out Form W-4 with your employer. If you expect to owe tax at the end of the year, you can ask your employer to withhold more from each check. This spreads your tax payment throughout the year instead of owing a lump sum on April 15.

Changing your withholding takes effect on your next paycheck, so if you realize in March that you will owe, you can increase withholding for the last few paychecks of the year. This reduces what you owe on April 15, though it does not eliminate it if you have already earned most of your income for the year.

State income tax important date

Most states with an income tax follow the federal April 15 important date. However, some states have different dates or different rules. A few states do not have income tax at all (including Florida, Texas, and Wyoming), so you only owe federal tax.

If you live in one state and work in another, you may owe tax to both. Your employer withholds tax for the state where you work, but you file a return in your state of residence. Some states offer credits to avoid double taxation, but you have to claim them on your return.

State penalties for late filing and late payment vary. Some states charge penalties similar to the federal rates; others charge less or more. Check your state's tax agency website for the exact important date and penalty structure in your state.

Frequently Asked Questions

What if April 15 falls on a weekend or holiday?

The important date automatically moves to the next business day. For example, if April 15 is a Saturday, your important date is Monday, April 17. The IRS announces the exact date each year on its website. State important date follow the same rule.

Do I have to pay estimated quarterly taxes if I have a W-2 job?

No, not usually. Your employer withholds tax from your paychecks, so you do not owe estimated quarterly taxes. However, if you have side income, investment income, or other earnings not subject to withholding, you may owe estimated taxes on that income even if you have a W-2 job.

Can I pay my taxes in installments without a formal payment plan?

You can pay whenever you want throughout the year, but the IRS considers any unpaid balance due on April 15. If you pay after April 15 without a formal plan, you owe failure-to-pay penalties and interest. A formal payment plan stops the failure-to-pay penalty from growing as long as you stick to the schedule.

What if I owe federal tax but my state has no income tax?

You still owe federal tax by April 15. State income tax is separate from federal tax. If your state has no income tax, you only file a federal return and owe federal tax. Some states require you to file a return anyway to claim credits or report other income.

Does filing an extension give me more time to pay?

No. An extension gives you until October 15 to file your return, but tax is still due April 15. If you do not pay by April 15, you owe penalties and interest on the unpaid amount. The extension is useful if you need time to gather documents or calculate your numbers, not if you need time to save money.