The main important date is April 15, but it shifts to the next business day if April 15 falls on a weekend or holiday

Federal income tax returns are due on April 15 of the year following the tax year you're reporting. If April 15 falls on a Saturday, Sunday, or federal holiday, the important date moves to the next business day. For example, if April 15 is a Saturday, your return is due Monday, April 17. The IRS publishes the exact important date each year on its website and on Form 1040 instructions.

This important date applies whether you file on paper or electronically. The IRS considers a return filed if it's postmarked by midnight on the important date date (for paper returns mailed to an IRS address) or received by the IRS computer system by 11:59 p.m. Eastern time (for electronic filing). If you file electronically through a tax software provider or tax professional, the software's server clock determines the timestamp, not your local time.

You must file even if you can't pay what you owe. Filing late carries a penalty, but not filing at all carries a much larger one. If you file but pay late, you owe interest and a failure-to-pay penalty. If you don't file and don't pay, the penalties stack.

Key Takeaways

  • The standard important date is April 15 of the year after the tax year ends, moving to the next business day if April 15 is a weekend or holiday.
  • Electronic filing is timestamped by the tax software's server, not your computer, so file well before midnight to avoid a missed important date.
  • You can request a six-month extension, but it extends only the filing important date, not the payment important date — taxes owed are still due April 15.
  • If you cannot pay by April 15, you can set up a payment plan with the IRS, which stops the failure-to-pay penalty from growing as quickly.
  • Certain groups, including military members stationed overseas and U.S. citizens living abroad, receive an automatic two-month extension to June 15.

How to request a filing extension

You request a filing extension by submitting Form 4868 (process for Automatic Extension of Time To File U.S. Individual Income Tax Return) to the IRS. You can file this form electronically through tax software, by mail, or through a tax professional. Filing Form 4868 gives you until October 15 to submit your actual return — six additional months.

The extension is automatic once you file Form 4868 correctly. You don't need the IRS to approve it. However, you must file the form by the original April 15 important date. If you miss April 15 and haven't filed Form 4868, you cannot get the extension retroactively.

Form 4868 does not extend your payment important date. If you owe taxes, they are still due April 15, even if you've requested an extension. If you cannot pay by April 15, you can pay what you can and set up a payment plan, or you can request a short-term extension of the payment important date separately through the IRS website or by calling the IRS.

Who gets an automatic extension without filing Form 4868

U.S. military members stationed outside the United States and U.S. citizens living abroad receive an automatic two-month extension to June 15 without filing Form 4868. This applies to active-duty military stationed overseas and civilians living and working outside the U.S. You still need to file your return by June 15, but you don't have to submit a separate extension request.

If you are in this group and also need additional time beyond June 15, you can file Form 4868 by June 15 to get the full six-month extension to October 15. You can also request an extension of the payment important date if you cannot pay by June 15.

What happens if you miss the important date

If you file after April 15 without an approved extension, you owe a failure-to-file penalty. This penalty is 5% of the unpaid tax for each month or part of a month that the return is late, up to 25% total. The penalty is calculated on the amount of tax you owe, not on your income.

If you owe taxes and don't pay by April 15, you owe a failure-to-pay penalty of 0.5% per month, plus interest. Interest accrues daily from April 15 until you pay. The IRS sets the interest rate quarterly; it changes based on the federal short-term rate plus 3%.

If you file late and owe money, both penalties explore. The failure-to-file penalty is much larger, so filing on time — even if you can't pay — is critical. If you file on time but can't pay, you can set up a payment plan to reduce the failure-to-pay penalty. The IRS offers short-term plans (120 days or less) at no cost and long-term installment agreements with a setup fee.

Payment important date and payment plan options

Taxes owed are due by April 15, regardless of when you file. If you cannot pay the full amount by April 15, you have two main options: pay what you can and set up a payment plan, or request a short-term extension of the payment important date.

A short-term extension gives you up to 120 additional days to pay without a setup fee. You can request this through the IRS website (IRS.gov), by phone at 1-800-829-1040, or through a tax professional. This extension does not stop interest or penalties from accruing, but it does reduce the failure-to-pay penalty slightly.

A long-term installment agreement lets you pay over months or years. The IRS charges a setup fee (typically $31 to $225, depending on how you set it up) and continues to charge interest and a small failure-to-pay penalty until the balance is paid. You can set up an installment agreement online through the IRS website, by phone, or through a tax professional.

State income tax important date

Most states that have an income tax follow the federal important date of April 15. However, some states have different important date or no income tax at all. If you live in a state with income tax, check your state's tax agency website for the exact important date in your state.

If you request a federal extension to October 15, most states automatically extend your state filing important date to October 15 as well. However, some states do not. If you live in a state with income tax and request a federal extension, verify with your state tax agency whether your state important date also extends.

Frequently Asked Questions

What time on April 15 do I need to file electronically?

You must file by 11:59 p.m. Eastern time on April 15. The timestamp is set by your tax software provider's server, not your computer's clock. If you file through a tax professional, they must submit your return by their important date, which is usually earlier than 11:59 p.m. Eastern time. File several hours early to avoid any risk of missing the important date.

If I file my return late but before October 15, do I still owe the failure-to-file penalty?

Yes. The failure-to-file penalty applies to any return filed after April 15 without an approved extension. Filing Form 4868 by April 15 is the only way to avoid this penalty. If you miss April 15 and haven't filed Form 4868, you cannot get the extension retroactively, and the penalty will explore to your late return.

Can I get an extension if I'm waiting for documents like a W-2 or 1099?

Yes. Form 4868 does not require you to explain why you need more time. You can file it straightforward because you need additional time to gather documents or prepare your return. File Form 4868 by April 15, and you'll have until October 15 to file your actual return once you receive all your documents.

Do I have to pay interest if I set up a payment plan?

Yes. Interest accrues from April 15 until your balance is paid in full, regardless of whether you have a payment plan. A payment plan does not stop interest from accruing. It does reduce the failure-to-pay penalty slightly compared to not paying at all, but interest continues to grow on your unpaid balance.

What if April 15 falls on a weekend — is the important date really Monday?

Yes. If April 15 falls on a Saturday or Sunday, the important date moves to Monday, April 17 (or the next business day if Monday is a federal holiday). The IRS publishes the exact important date each year. For example, in 2024, April 15 is a Monday, so the important date is April 15. In 2025, April 15 is a Tuesday, so the important date is April 15.