Overview

Federal filing extensions give you more time to file federal tax returns (individuals commonly get six months after filing Form 4868) but rarely extend the time to pay taxes owed. The IRS clearly states that an extension to file is not an extension to pay; interest and penalties can still apply to unpaid balances after the original due date (see IRS Form 4868 guidance) [https://www.irs.gov/forms-pubs/about-form-4868].

How federal extensions work

  • Individuals use Form 4868 to request an automatic six-month extension to file federal returns; businesses generally use Form 7004 for many business returns [https://www.irs.gov/forms-pubs/about-form-7004].
  • Filing either form extends only the time to file, not to pay federal taxes due. Pay as much as you can by the original due date to reduce interest and late-payment penalties.
  • States set their own rules. Some accept the federal extension or automatically follow federal moves; others require a separate state extension form or electronic request.

State variation — examples

  • California: For many individual filers, California grants an extension to file when you’ve been granted a federal extension. Confirm details with the Franchise Tax Board and whether you still need to pay by the original due date [https://www.ftb.ca.gov/].
  • New York: New York requires a separate state extension or filing of its extension procedures; do not assume a federal extension covers NY state filing obligations [https://www.tax.ny.gov/].

In my practice, the most frequent problem I see is taxpayers who file a federal extension but neither make an estimated state payment nor file the separate state extension where required; that combination typically generates penalties and interest.

Practical steps to avoid trouble

  1. Check your state’s rules early. Use your state’s tax agency website for authoritative guidance (for example, CA and NY links above).
  2. File the federal extension on time (Form 4868) to secure the federal filing delay.
  3. If your state requires a separate extension, file it before the state deadline. See our guide: How to Request an Extension for State and Federal Returns for step-by-step instructions.
  4. Pay what you owe by the original due date (federal and state) or make an estimated payment to limit penalties and interest.
  5. Keep documentation of payments and extension confirmations in case of disputes.

Business filers

  • Corporations and many pass-through entities use Form 7004 for federal extensions; states often require their own forms or payments. Check state business filing guidance and your state’s due dates.

Common mistakes

  • Assuming a federal extension automatically covers your state return.
  • Thinking extension equals extra time to pay; penalties and interest can accrue from the original due date.
  • Missing state-specific rules for business versus individual returns.

Quick checklist

  • File Form 4868 (individuals) or Form 7004 (businesses) if you need federal extra time.
  • Confirm whether your state accepts the federal extension or needs a separate request.
  • Pay as much as you can by the original due date.
  • Save confirmations and receipts.

Internal resources

Authoritative sources

Professional disclaimer

This entry is educational and does not replace personalized tax advice. Rules change and states update procedures; consult a qualified tax professional or your state tax agency for guidance specific to your situation.