How to File a Tax Extension Without Penalties

Learn how to properly file Form 4868 for a tax extension and avoid IRS penalties with the right timing and payment strategy.

1. File Form 4868 by the original deadline. Submit Form 4868 (Application for Automatic Extension of Time To File) by April 15. You can file online through the IRS website, use tax software, or mail a paper form. No explanation or justification required — the extension is automatic if you file on time.
2. Estimate and pay what you owe. Calculate your expected tax liability and pay at least 90% of what you owe by April 15. You can pay online, by phone, or mail a check with Form 4868. This payment prevents late-payment penalties even if your final amount differs.
3. Keep records of your extension filing. Save confirmation numbers from electronic filings or certified mail receipts for paper forms. Print or screenshot your filing confirmation. The IRS doesn't send acknowledgment letters for extensions, so your records are your proof.
4. File your actual return by October 15. Complete and submit your full tax return by the extended deadline. If you owe additional taxes beyond what you paid in April, include payment with your return. Missing this second deadline triggers both late-filing and late-payment penalties.