🇺🇸 United States

Form 4868 Tax Extension

6-Month Tax Filing Extension

Easy ~5 min TaxExtensionIRSDeadline

/ What is this form?

Form 4868 gives an automatic 6-month extension to file your federal income tax return, moving the deadline from April 15 to October 15. No approval is needed — it's automatic if filed by April 15.

Critically, Form 4868 only extends the time to file — not the time to pay. Any tax you owe is still due April 15. If you don't pay by then, interest and a failure-to-pay penalty (0.5% per month) will accrue on the unpaid balance.

Filing an extension also extends state tax deadlines in most states, but verify your state's rules.

/ Who needs this form?

Anyone who cannot complete their tax return by April 15
People still waiting for tax documents such as partnership K-1s
People in complex financial situations that take more time to document

/ What you need before you start

Social Security Number

Estimated total tax liability for the year

Amount already paid through withholding and estimated payments

/ Step-by-step guide

1 Estimate Your Tax Liability

Calculate your best estimate of total tax owed for the year. You need this even if you don't have all documents yet.

2 Determine What You've Already Paid

Add up withholding from W-2s and any estimated quarterly payments made.

3 File Form 4868

Submit Form 4868 electronically (free through IRS Free File or tax software) or by mail by April 15.

4 Pay Any Balance

Pay your estimated balance due by April 15. The extension extends the filing deadline, not the payment deadline.

5 File by October 15

You now have until October 15 to file your complete return. File as soon as you have all documents.

/ Key fields explained

Field	What to enter	Common mistake
Estimated tax liability	Your best estimate of the total federal income tax you owe for the year.	Leaving this blank or entering $0 — even a rough estimate is required.

/ Common mistakes to avoid

Thinking the extension means you don't have to pay until October — you must pay by April 15.

Not filing the extension by April 15 — it must be filed, not just postmarked, by the deadline.

Not filing a state extension — most states require a separate state extension or have different rules.

/ Frequently asked questions

Is the extension automatic?

Yes. If filed by April 15, there is no approval process — the extension is granted automatically. You move to an October 15 deadline.