How to file a tax extension online
You file a tax extension online through the IRS using Form 4868, which you can submit electronically through IRS Free File, tax software, or a tax professional's portal. The extension gives you until October 15 to file your return instead of April 15 — it does not extend the deadline to pay taxes owed. You must file Form 4868 by the original tax deadline (usually April 15) to get the extension; filing it after that date does not count.
The IRS processes most online extensions immediately, and you receive confirmation right away. You do not need to wait for approval — if you file the form by the deadline, the extension is automatic. However, you still owe any taxes due by April 15, even if you do not file your return until October.
Key Takeaways
- Form 4868 must be filed by April 15 to extend your deadline to October 15; filing after April 15 does not grant an extension.
- You can file Form 4868 through IRS Free File, commercial tax software, or a tax professional without paying a fee through Free File.
- An extension to file is not an extension to pay — taxes owed are still due April 15, and the IRS charges interest and penalties on late payments.
- The IRS confirms your extension immediately after you file online; you receive a confirmation number you should save for your records.
Filing through IRS Free File
IRS Free File is the official free online filing system run by the IRS in partnership with tax software companies. You access it through IRS.gov, and it includes the ability to file Form 4868 at no cost if your income is below the annual threshold (which changes yearly). You do not enter any payment information or credit card details to use Free File for an extension.
To use Free File, go to IRS.gov/freefile, select your state and income level, and choose from the list of participating software providers. Each provider offers a free version that includes Form 4868. You create an account, enter your personal information, and file the form electronically. The system confirms your submission immediately and provides a confirmation number.
If your income is above the Free File threshold, you can still file Form 4868 for free through IRS Free File's fillable forms option, which lets you complete and submit the form without using tax software.
Filing through tax software
Most commercial tax software — TurboTax, H&R Block, TaxAct, and others — includes Form 4868 filing as part of their standard or premium packages. Some charge a fee to file the extension, while others include it at no cost. Check the software's pricing page or ask before you purchase to confirm whether Form 4868 filing is included.
Once you have the software open, look for an option labeled "File an Extension" or "Form 4868" in the main menu. The software walks you through entering your name, Social Security number, address, and estimated tax liability. You review the completed form, then submit it electronically. The software provides a confirmation number and typically emails you a copy of the filed form.
If you have already started your tax return in the software, you can usually file an extension without completing the entire return. You provide only the information Form 4868 requires: your identification, address, and an estimate of what you owe.
Filing through a tax professional
If you work with a CPA, tax attorney, or enrolled agent, they can file Form 4868 on your behalf electronically. You sign a power of attorney form (usually Form 2848) that authorizes them to represent you with the IRS. They then file the extension using their professional tax software and credentials.
A tax professional typically charges a fee for this service, though some include it as part of a larger tax preparation package. Confirm the cost before you authorize them to file. Once they submit the form, you receive a confirmation number and a copy of the filed extension.
What information you need to file
Form 4868 requires basic information: your name, address, Social Security number (or ITIN), and filing status. You also need to estimate your total tax liability for the year — this is your best guess at what you will owe after accounting for withholding and any payments you have already made.
If you file jointly, both spouses must sign the form (or both must authorize it electronically if filing online). If you are filing on behalf of a business or partnership, you need the employer identification number (EIN) instead of a Social Security number.
You do not need to attach any documents, receipts, or financial statements to file the extension. Form 4868 is a simple form that takes 10 to 15 minutes to complete once you have your information gathered.
What happens after you file the extension
The IRS sends you a confirmation notice (usually by mail within two weeks) showing that your extension was received and processed. Keep this notice with your tax records. The confirmation includes a confirmation number you can reference if you have questions later.
Your new filing deadline is October 15. You can file your actual tax return anytime between now and then. If you file before October 15 and owe additional taxes, you owe interest and penalties on the unpaid amount from April 15 forward, even though you filed the extension.
If you do not file your return by October 15, the extension expires and you are considered late. The IRS charges a failure-to-file penalty on top of any taxes owed, plus interest from April 15.
Important limits on extensions
Form 4868 extends your filing deadline, but it does not extend your payment deadline. Any taxes you owe are due April 15, regardless of when you file your return. If you cannot pay by April 15, you can request a payment plan (installment agreement) or an offer in compromise, but these are separate from the filing extension.
You can file only one extension per tax year. If you file Form 4868 and then need more time, you cannot file another extension form. Your deadline remains October 15.
An extension is available to all taxpayers, but it does not prevent the IRS from auditing your return or assessing penalties if you owe taxes. Filing an extension does not reduce your tax liability or change what you owe.
Frequently Asked Questions
What if I miss the April 15 deadline to file the extension?
If you file Form 4868 after April 15, the IRS does not grant an extension. You are considered late, and the failure-to-file penalty applies. However, you can still file your return and pay any taxes owed; the penalty is calculated based on how late you are.
Do I have to pay anything to file the extension online?
No. Filing Form 4868 itself is free through IRS Free File or through a tax professional. Some commercial tax software charges a fee to file the extension, but you can always use Free File at no cost. You do not owe any taxes to file the extension — you pay taxes only when you file your actual return.
Can I file an extension if I expect a refund?
Yes. An extension applies to all taxpayers regardless of whether they owe or expect a refund. However, if you are expecting a refund, filing the extension delays when you receive it. You can file your return early and get your refund without waiting until October.
What if I file the extension but then file my return early?
You can file your return anytime after you file the extension, even before October 15. Once you file your actual return, the extension is no longer needed. If you owe taxes, they are due April 15 regardless of when you file the return.
Does the extension apply to state taxes too?
No. Form 4868 extends only your federal tax deadline. Most states have their own extension forms and deadlines. Check your state tax agency's website to file a state extension separately if you need one.