Background

Federal filing deadlines are set by the Internal Revenue Service (IRS) and vary by taxpayer type and entity structure. Individual returns (Form 1040) are generally due in mid‑April each year, while partnerships and S corporations typically have earlier spring deadlines. Extensions provide automatic additional time to file the return, but not to pay tax owed. In my practice as a CPA and CFP®, I consistently see taxpayers avoid penalties by timely requesting extensions and making estimated payments when needed.

How extensions work (quick overview)

  • Individuals: File Form 4868 (Application for Automatic Extension of Time To File U.S. Individual Income Tax Return) to get an automatic six‑month extension to file—generally moving an April due date to mid‑October. Form 4868 does not extend the time to pay; payments should be made by the original due date. (IRS: About Form 4868)
  • Businesses: Use Form 7004 (Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns). Deadlines and extension lengths differ by entity: for many corporations the extension is six months, while partnerships and S corporations generally receive six months from their original March due date. (IRS: About Form 7004)
  • Payments: Taxes owed remain due on the original deadline. Interest and penalties accrue on unpaid balances from that date. See IRS penalty rules for failure to file and failure to pay. (IRS: Penalties)

Key deadlines and examples

  • Individual (calendar year): Form 1040 due in mid‑April; Form 4868 typically extends filing to mid‑October.
  • Partnerships and S corporations: Return due in mid‑March; a six‑month extension commonly moves filing into mid‑September.
  • C corporations (calendar year): Return due in mid‑April; extensions commonly move the filing deadline six months later.

Real‑world examples

  • Individual: A self‑employed consultant who files Form 4868 and pays estimated tax by the April due date avoids the failure‑to‑file penalty even though the return is submitted in October.
  • Business: A small bakery organized as an S corporation filed Form 7004 to gain six months to collect financial statements and finalize deductions.

Who is affected and eligibility

All U.S. taxpayers with federal filing obligations—individuals, partnerships, corporations, estates, and trusts—are subject to filing deadlines. Most taxpayers can request automatic extensions by filing the proper IRS form (4868 for individuals; 7004 for many business returns). Certain taxpayers (e.g., U.S. citizens abroad, disaster victims, or military personnel) may have different or additional relief; consult the IRS pages and special‑status guidance.

Payments, estimated taxes, and penalties

  • Paying by the original deadline is crucial. Extensions do not stop interest or penalties on unpaid taxes.
  • Failure‑to‑file penalty: generally 5% of the unpaid tax per month (up to a maximum, commonly 25%); higher if fraud is involved.
  • Failure‑to‑pay penalty: generally 0.5% per month on unpaid tax (also up to a limit—commonly 25%).
  • To reduce penalties and interest, make an estimated payment or use IRS payment options such as Direct Pay or EFTPS.

Common mistakes and misconceptions

  • Believing an extension delays tax payment. It does not.
  • Assuming state deadlines match federal ones — many states have different rules and may require separate extension requests.
  • Waiting until the last day to submit the extension form; while the IRS grants automatic extensions when the form is timely filed, payment channels can be overloaded close to deadlines.

Practical tips I use with clients

  1. Estimate and pay: If you expect to owe, estimate your tax and pay at least what you owe by the original deadline to avoid failure‑to‑pay penalties.
  2. File electronically: Both extension forms can be submitted electronically, which gives reliable timestamps and confirmations.
  3. Keep records: Save proof of payment or confirmation of extension filings; this helps if you later request penalty relief.
  4. Coordinate state filings: Check your state revenue department rules; many require a separate extension or payment.

Where to find help and next steps

  • Read the IRS guidance for Form 4868 (individual extensions) and Form 7004 (business extensions).
  • If you missed a deadline, file as soon as possible and pay what you can; filing reduces the failure‑to‑file portion of penalties and starts the clock on appeals or relief requests.

Internal resources

Authoritative sources

Professional disclaimer

This content is educational and general in nature. It does not replace personalized tax advice. For guidance specific to your situation, consult a qualified tax professional or the IRS.