At-a-Glance: Form 4868
What Is Form 4868?
Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return, gives you an automatic 6-month extension to file your federal tax return. This moves your filing deadline from April 15 to October 15. Important: This is an extension to file, not an extension to pay — you must still estimate and pay any taxes owed by April 15.
Why You Might Need Form 4868
You may need Form 4868 if you can't file your tax return by the April deadline. Common reasons include:
- •You're waiting for tax documents (K-1s, 1099s, etc.)
- •Your tax situation is complex and your preparer needs more time
- •You're overseas and need additional time
- •You experienced a life event (illness, disaster) that delayed preparation
- •You want to ensure accuracy rather than rush your return
Where to Fax Form 4868 in 2026
Official IRS Fax Numbers
Note: IRS fax numbers can change. Always verify on the latest form instructions before sending. Last verified: March 2026.
Source: IRS.gov — About Form 4868
Disclaimer: This page is for informational purposes only and does not constitute tax, legal, or financial advice. FaxFlow is a fax transmission service — we are not tax professionals and do not provide tax advice. Always consult a qualified tax professional or CPA for guidance specific to your situation. Verify all IRS fax numbers and form requirements on IRS.gov before submitting.
Step-by-Step: How to Fill Out & Fax Form 4868
Estimate Your Tax Liability
Calculate your expected tax for the year. The extension is for filing, not paying — you must pay estimated taxes by April 15.
File Electronically (Recommended)
E-file Form 4868 through IRS Free File or your tax software for instant confirmation.
Or Download Form 4868
If e-filing isn't an option, download the paper form from IRS.gov.
Make Any Required Payment
Pay your estimated tax balance by April 15 to avoid penalties and interest.
Mail or Fax to Your Tax Professional
If filing by paper, mail to the address on the form. Use FaxFlow to send a copy to your CPA.
Using FaxFlow to Send Form 4868 Easily
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E-file at IRS.gov/E-file (pre-saved)
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Start Faxing NowCommon Mistakes to Avoid
- •Thinking the extension applies to payment — you still owe taxes by April 15
- •Not estimating your tax liability, leading to underpayment penalties
- •Filing the extension after the April 15 deadline
- •Forgetting to actually file your return by October 15
- •Not making a payment with the extension when taxes are owed
FAQ Section
Does Form 4868 extend the time to pay?
No. Form 4868 only extends the time to file your return. You must still estimate and pay any taxes owed by April 15 to avoid penalties and interest.
How do I file Form 4868?
The easiest way is to e-file through IRS Free File at IRS.gov. You can also file through tax software, your tax professional, or by mailing the paper form.
What is the new deadline after filing Form 4868?
Filing Form 4868 gives you an automatic 6-month extension, moving your deadline from April 15 to October 15.
Will I be penalized for filing an extension?
No. There is no penalty for filing an extension, as long as you pay at least 90% of your estimated tax by April 15.
Can I file Form 4868 from my phone?
Yes. You can e-file through the IRS2Go mobile app or use FaxFlow to fax the paper form to your tax professional for processing.
Ready to Fax Your Form 4868?
Skip the trip to a fax machine. Send your extension of time to file securely from any device.