You file a tax extension by submitting Form 4868 to the IRS before your tax deadline

A tax extension gives you six additional months to file your tax return — moving your deadline from April 15 to October 15 in 2024. Filing the extension itself takes 15 minutes and costs nothing. The extension does not give you extra time to pay taxes owed; you still owe payment by April 15 if you expect to owe money. Most people file extensions because they need more time to gather documents, wait for forms from employers or financial institutions, or work with a tax professional who is busy.

You can file Form 4868 online through the IRS website, through tax software, by phone, or by mailing a paper form. The IRS accepts extensions filed up until the original April 15 deadline. If you miss that date, you cannot file an extension retroactively.

Key Takeaways

  • Form 4868 extends your filing deadline to October 15, 2024, but does not extend the payment deadline — taxes owed are still due April 15.
  • You can file the extension online through IRS.gov, through tax software like TurboTax or H&R Block, by phone at 1-888-796-1074, or by mailing a paper form.
  • Filing an extension takes about 15 minutes and is free; you do not need to explain why you need more time.
  • If you expect to owe taxes, estimate what you owe and pay it by April 15 to avoid penalties and interest charges.
  • An extension does not reduce what you owe or change your tax liability — it only changes when you file the return itself.

Filing Form 4868 online through the IRS

The fastest way to file an extension is through the IRS Free File program on IRS.gov. Go to irs.gov/freefile, select your income level and state, and choose a participating tax software provider. Most providers offer a free version that includes Form 4868 filing. You will enter basic information — your name, Social Security number, address, and expected income — and the software will submit the form electronically to the IRS.

If you do not may have access to for Free File (usually because your income is above the threshold, which varies by year), you can purchase tax software that includes extension filing. TurboTax, H&R Block, and other commercial providers all allow you to file Form 4868 for a fee, typically $15 to $30. You do not need to file your full tax return to file an extension; you can file the form alone and complete your return later.

The IRS typically confirms receipt of an electronically filed extension within 24 hours. You will receive a confirmation number; save this for your records.

Filing by phone or mail if you prefer not to go online

You can file an extension by calling the IRS at 1-888-796-1074. An IRS representative will ask for your name, Social Security number, address, and expected income or tax liability. The call takes about 10 minutes. You will receive a confirmation number by phone; write it down immediately.

If you prefer to mail Form 4868, download it from irs.gov or request it by phone. Fill out the form with your name, Social Security number, address, and expected income. Mail it to the IRS address listed on the form instructions — the address depends on your state. The IRS must receive it by April 15, 2024. Mailing takes longer than electronic filing, so mail it at least one week before the deadline to account for postal delays.

What to do if you expect to owe taxes

An extension only delays filing your return, not paying your taxes. If you expect to owe money, estimate how much and pay it by April 15, 2024 — the same date your return would normally be due. You can pay online through IRS.gov, by phone, by mail, or through your bank's bill-pay system. Paying on time stops interest and penalties from accruing.

If you file the extension but do not pay by April 15, the IRS will charge interest on the unpaid balance starting April 16. The interest rate changes quarterly; in 2024 it is 8 percent per year. You will also owe a failure-to-pay penalty of 0.5 percent per month on any unpaid taxes, up to 25 percent total. These charges add up quickly, so paying your estimate by the April deadline is important even if your exact tax liability changes later.

When you file your actual return in the fall, if you paid more than you owe, you will receive a refund. If you paid less, you will owe the difference plus any additional interest that accrued between April 15 and the date you file.

What happens after you file the extension

After you file Form 4868, you have until October 15, 2024 to file your tax return. You do not need to do anything else; the extension is automatic once the IRS receives the form. You can file your return anytime between now and October 15 — you do not have to wait until October.

If you filed an extension but realize you will not need it, you can still file your return early. There is no penalty for filing before October 15. Many people file extensions out of caution and then complete their returns in May or June.

If you file the extension but miss the October 15 deadline without filing a return, the IRS will treat you as having not filed. This triggers failure-to-file penalties on top of any taxes owed, plus interest. The failure-to-file penalty is 5 percent per month, much steeper than the failure-to-pay penalty. If you think you will miss the October deadline, contact the IRS before October 15 to discuss your options.

Extensions for people who live or work outside the United States

If you are a U.S. citizen or resident alien living outside the country, you automatically receive a two-month extension to June 15, 2024 without filing Form 4868. If you need more time beyond June 15, you can file Form 4868 to extend to October 15. The same rules apply: the payment deadline is still April 15, and you owe interest and penalties on any unpaid taxes after that date.

If you are a member of the military serving outside the United States, you also receive an automatic two-month extension. File Form 4868 if you need to extend beyond that.

Common reasons people file extensions and what to expect

The most common reason for filing an extension is waiting for documents. If your employer has not sent your W-2 by early April, or your brokerage has not sent your 1099 forms, you cannot complete your return. Filing an extension buys you time without penalty. The IRS knows that some employers and financial institutions file documents late.

Self-employed people and business owners often file extensions because their bookkeeping is not finished by April. If you run a business, you may not know your final income or deductible expenses until later in the year. An extension gives you time to organize records and work with an accountant.

People with complex returns — multiple rental properties, significant investment income, or business ownership — often file extensions because they need time to work with a tax professional. Tax preparers are busiest in March and early April; filing an extension moves your appointment to May or June when they have more availability.

Frequently Asked Questions

Does filing an extension delay when I have to pay taxes?

No. The extension delays when you file your return, not when you pay. Taxes owed are due April 15, 2024, whether you file an extension or not. If you do not pay by April 15, you owe interest and penalties on the unpaid balance starting April 16, even if you do not file your return until October.

What if I file an extension but do not file a return by October 15?

The IRS treats you as having not filed. You will owe failure-to-file penalties of 5 percent per month on top of any taxes owed, plus interest. This penalty is much steeper than the failure-to-pay penalty. Contact the IRS before October 15 if you think you will miss the deadline.

Can I file an extension after April 15?

No. The IRS must receive Form 4868 by April 15, 2024. If you miss that deadline, you cannot file an extension retroactively. If you have not filed a return and did not file an extension, contact the IRS immediately to discuss your options.

Do I need to explain why I need an extension?

No. Form 4868 does not ask for a reason. You do not need to justify why you need more time. Simply file the form with your basic information and the IRS will grant the extension.

What if my income changes after I file the extension?

Your extension estimate does not lock in your tax liability. When you file your actual return in the fall, you report your real income and deductions. If you owe more than you estimated and paid, you will owe the difference plus interest. If you owe less, you will receive a refund or credit toward next year's taxes.