Form 4868: More Time to File, Not to Pay
Published November 4, 2026
Form 4868 gives you more time to file your federal income tax return. It does not give you more time to pay. That difference causes most of the trouble people have with extensions. IRS: Get an extension to file your tax return
The deadline
For the 2026 tax year, the IRS says the filing deadline for most people is April 15, 2027. You must file Form 4868 by that date to get the extension. IRS: When to file
Most calendar-year filers get an automatic six-month extension. For most people, that runs to October 15, 2027. You do not need approval, and you do not have to give a reason. The IRS says it will contact you only if a request is denied. IRS: Topic 304 · IRS: Form 4868 instructions (2025 PDF)
An extension to file is not an extension to pay
The tax you owe is still due April 15, 2027. If you do not pay by then, underpayment interest starts on that date, even if you have an extension. Interest keeps adding up until the balance is paid. The IRS changes interest rates each quarter, so check IRS.gov for current rates. IRS: Interest
How to estimate what you owe
Form 4868 asks you to estimate your total tax for the year. Then subtract what you already paid through withholding and estimated payments. The result is the amount you expect to owe. You can pay all or part of that estimate with your request. If you pay less than the full amount, the rest still earns interest and may bring penalties. Any payment you make with the request counts as a payment of tax.
Estimate honestly, using the information you have. Keep the papers you used to make the estimate.
Three ways to request it
- Pay and indicate an extension. Pay part or all of your estimate through IRS Direct Pay, your online account, EFTPS, a debit or credit card, or a digital wallet. Tell the payment system that the payment is for an extension of time to file. You get a confirmation number. You do not need to file Form 4868 separately.
- File electronically. Use IRS Free File, tax software that offers Form 4868, or a tax professional who uses e-file. You get an electronic acknowledgment. Keep it.
- File on paper. Mail a paper Form 4868 to the address listed in the form instructions. A payment with the paper form is optional.
Penalties and interest in brief
Two penalties can apply when a return or payment is late:
- Failure to file: usually 5% of the unpaid tax for each month or part of a month the return is late, up to 25%. The due date includes extensions, so this penalty does not apply if you file by the extended date.
- Failure to pay: 0.5% of the unpaid tax for each month or part of a month after the April due date, up to 25%. It applies even when you have an extension. If you filed on time and have an approved payment plan, the rate drops to 0.25% per month.
Illustration only, with round numbers: Suppose you owe $1,000 for 2026. You file with an extension by October 15, 2027, and you pay the tax two months after April 15. The failure-to-pay penalty would be 0.5% a month for two months, or $10. Interest is added on top. These are round examples, not a calculation for your return.
If you cannot pay in full, an installment agreement lets you pay the balance over time. You can apply online, by phone, or by mailing Form 9465. Interest keeps running on what you still owe. IRS: Payment plans · IRS: Penalties
Special cases
If you live outside the United States, you may get an automatic two-month extension on your regular due date. You can request four more months with Form 4868. Military service in a combat zone and some federally declared disasters can also give more time. Check IRS.gov or Publication 54 for your situation. IRS: Topic 304
Common mistakes
- Thinking an extension delays the tax bill. It does not.
- Assuming an extension stops interest. It does not.
- Filing Form 4868 after April 15. The request must be made by the original due date.
- Keeping no proof. Save the confirmation number or the electronic acknowledgment.
Checklist
- Note April 15, 2027 (original due date) and October 15, 2027 (extended filing date).
- Estimate your total tax for the year and subtract what you already paid.
- Pay the estimate, or as much as you can, by April 15.
- Choose one way to request the extension and save the confirmation.
- If you cannot pay in full, look at an installment agreement before penalties grow.
If you are already late, read What Happens If I File Late or Can't Pay What I Owe?
General information, not advice for your return.
Sources: IRS: Get an extension to file your tax return (https://www.irs.gov/filing/get-an-extension-to-file-your-tax-return); IRS: When to file (https://www.irs.gov/filing/individuals/when-to-file); IRS: Topic 304 (https://www.irs.gov/taxtopics/tc304); IRS: Form 4868 instructions, 2025 PDF (https://www.irs.gov/pub/irs-pdf/f4868.pdf); IRS: Interest (https://www.irs.gov/payments/interest); IRS: Penalties (https://www.irs.gov/payments/penalties); IRS: Payment plans (https://www.irs.gov/payments/payment-plans-installment-agreements) This is general information, not advice about your specific return.
