How do I file a tax extension if I can't finish my return by April 15, 2025?

Filing a tax extension is straightforward and gives you an automatic 6 extra months to file your return — pushing your deadline from April 15 to October 15, 2025. Here's exactly how to do it:

How to file Form 4868:

• Online (easiest): Use IRS Free File at IRS.gov to submit Form 4868 electronically at no cost, even if your income exceeds the Free File limit.
• Through your tax software: TurboTax, H&R Block, TaxAct, and similar software all have a built-in extension filing option.
• By mail: Download Form 4868 from IRS.gov, fill it out, and mail it postmarked by April 15. Mail to the address listed in the form's instructions based on your state.
• Pay and file: If you pay any estimated tax owed online via IRS Direct Pay or EFTPS and select "Extension" as the payment type, the IRS automatically treats that as a filed extension — no form required.

Critical rule — extension to file, NOT to pay:

An extension gives you more time to file, but not more time to pay. Any taxes you owe are still due on April 15. If you underpay, the IRS charges:

• Late payment penalty: 0.5% of unpaid tax per month (up to 25%)
• Interest: Currently around 7–8% per year (set quarterly at federal short-term rate + 3%)

To avoid penalties, estimate what you owe and pay at least 90% of your 2025 tax liability (or 100% of your 2024 tax liability, whichever is smaller) by April 15.

Who benefits most from an extension:

• K-1 partnership income that arrives late (common for April filers)
• Self-employed individuals with complex Schedule C situations
• Anyone waiting on corrected 1099s or W-2s
• Taxpayers with foreign income or accounts (note: FBAR is still due April 15 with an automatic extension to October 15 — no separate filing needed)

One thing extensions can't fix: If you owe taxes and don't pay by April 15, the extension doesn't prevent penalties. Pay as much as you can — even a partial payment reduces penalty accrual.