Here’s how to get the automatic tax return extension if you need more time to file

If you’re finding yourself contemplating whether you can get an extension on this year’s tax return, you’re not alone. Forty percent of Americans still haven’t filed.

There’s something almost perverse about the IRS placing tax day smack-dab in the middle of the loveliest month of the year. Want to enjoy the warm weather, cherry blossoms, and the sunshine reflecting off the pasty white skin of everyone venturing outside for the first time since last fall? Too bad! You have to excavate all of your financial decisions from the previous year while simultaneously trying to remember your math skills—or risk the wrath of an IRS agent named Spike.

That’s why it’s something of a relief that every American taxpayer can get an automatic six-month extension on filing their federal income taxes. But, since this is the IRS we’re dealing with, there is a catch: You still have to pay what you owe by Tax Day.

If filing your 2024 taxes has crept up on you this year (when did it get to be April already?), here’s what you need to know about getting an extension while staying on Spike the Auditor’s good side.

File for an extension with Form 4868

While all taxpayers are eligible for an automatic tax return extension, you still need to request one. That’s where Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return comes in.

Anyone who fills out and turns in Form 4868 (which can be filed electronically using IRS Free File) by the tax filing deadline of April 15, 2025, automatically receives a six-month extension for filing their 2024 taxes. This pushes the tax filing deadline back to October 15, 2025.

Unlike your 1040 and other required tax forms, Form 4868 does not require a great deal of information from you. All you need to provide on this form is the following

• Your name
• Current address
• Social Security number
• Estimated tax liability for 2024
• Amount of 2024 tax you have already paid

The form also asks you to subtract your total 2024 payments from your estimated liability to calculate your balance due.

Once you have completed and filed the form, you will automatically receive the filing extension. Just remember that you’ve only extended the deadline for filing your tax paperwork. You still have to hand over your estimated tax liability by April 15.

Estimate your tax liability

If you, like me, have never once figured out your tax liability (or overpayment, in the years you get a return) without actually filing your taxes, you might be wondering how you’re supposed to calculate your estimated tax liability for Form 4868. It doesn’t help that the IRS offers this not-at-all ominous warning on Form 4868:

Make your estimate as accurate as you can with the information you have. If we later find that the estimate wasn’t reasonable, the extension will be null and void.

Just in case you weren’t already stressed about tax season.

Thankfully for those seeking a tax return extension, there are some guidelines for making a reasonable estimate of your tax liability.

Knowing what’s “reasonable”

Since one taxpayer’s “reasonable” is another’s “gross negligence,” the IRS helpfully defines a reasonable estimate as being 90% of the total tax you owe. If your estimate is at least 90% of the real number, and if you pay the remaining 10% or less balance when you file your tax return by the end of the six-month extension period, the IRS considers you all good.

W-2 employees

Traditionally employed taxpayers will typically have the easiest time estimating their liability. If you remained in the same job in 2023 and 2024 and your income didn’t change a great deal, you’ll just need to look back at your total tax liability for 2023. Go back to your 2023 tax return and check line 24, labeled your total tax.

When you’ve found your 2023 total tax number, subtract the following from it:

• Any taxes you have already paid in 2024, including
  • money withheld from your paychecks by your employer
  • any estimated tax payments you made
• Any 2024 tax credits you qualify for, including
  • the child tax credit
  • the child and dependent care credit
  • the earned income tax credit

Taking your 2023 total tax liability and subtracting any 2024 taxes paid and 2024 tax credits from it should give you a reasonable approximation of your current liability.

Self-employed taxpayers

Freelancers, gig workers, entrepreneurs, and small business owners seeking a tax return extension have a tougher task ahead of them when estimating their tax liability. Instead of a handy-dandy W-2, these taxpayers have to rely on their own records to know their income and estimate their taxes.

For these taxpayers, start with your total profits and losses from 2024 to get a back-of-the-envelope estimate of your income for the year. Plug that income estimate into a marginal tax rate calculator like this one from Bankrate to calculate your tax liability. Once you have that number, you can subtract any quarterly estimated taxes you paid in 2024, as well as any tax credits you qualify for. This should give you a reasonable estimate of your liability.

Job-hopping taxpayers

If you had more than one job in 2024, had an extreme change in your income, or otherwise had kind of a weird year money-wise, it’s probably best to calculate your tax liability with the IRS 1040-ES Estimated Tax Worksheet.

This is a 12-page form, which means it will take more work than filling out Form 4868. (It may even be the IRS’s Machiavellian scheme to encourage procrastinating taxpayers to just file their taxes already, since this requires almost as much work). But using the 1040-ES will give you the most accurate method of calculating your tax liability if you need to file for the extension.

Pay what you owe–or else pay even more

If you don’t cough up the taxes you owe by April 15, there will be consequences—of the financial variety.

The first consequence is a late payment penalty. This penalty charges you 0.5% of the unpaid taxes per month or partial month that the taxes remain unpaid. For example, let’s you owe Uncle Sam $5,000 for your 2024 taxes. Instead of making the $5,000 on April 15, you wait to pay until you file your tax return on October 15. You will face a 3.0% penalty or $150 because you made your payment six months after the April 15 deadline.

The second penalty you’ll face will be interest charged on your unpaid taxes, which can really be a pain in your bank account. The IRS sets its interest rate at the federal short-term rate, plus 3%, and it changes the rate on a quarterly basis. As of April 2025, the IRS currently charges an interest rate of 7% per year, compounded daily, for underpayment of individual taxes.

That means waiting until October 15 to pay your $5,000 in taxes would mean owing $178 in interest (provided the rate does not change). And that interest will continue to accrue until you pay what you owe.

Don’t forget about state taxes

If you live in a state with income tax, you probably need an extension for your state tax filing deadline, too. The good news is that many states automatically grant an extension for state taxes when you apply for a federal tax extension. But that’s not true of all states—some require a separate form to receive a state-level extension. You can find out what your state requires here.

Just remember that you also have to pay your state income tax by the spring tax deadline, even when you apply for a state-level extension. There’s no avoiding the spring tax payment.

Give yourself some breathing room

If tax season snuck up on you, an automatic extension can give you more time to file your taxes. Just remember that Uncle Sam still expects the money you owe him on April 15.