Don't panic if you haven't yet filed your tax return—you've still got time to file for an extension.gettyTax Day is almost here. If you’re not ready to file, you’re in good company—tens of millions of taxpayers (including me) will file for an extension this year, buying a little breathing room to file.Extensions can be a smart move. They give you time to gather documents, double-check complicated transactions, and avoid the kind of last-minute filing mistakes that can cause problems. The Basics of Filing for an Extension Filing for an extension gives you more time to file your return, not more time to pay your tax. If you expect to owe tax, the IRS still wants that money by April 15. Miss that, and you could be looking at penalties and interest, even if your extension is otherwise valid.Filing for an extension isn’t complicated, and the IRS gives you a few ways to do it. You can:File for an extension online for free using FreeFile on IRS.gov (you can use FreeFile to e-file an extension for free even if you don’t otherwise qualify to use the software).Ask your tax preparer to file an extension for you.Make an electronic payment using Direct Pay, debit card, credit card, or digital wallet, and indicate the payment is for an extension.File using tax prep software.Or, complete and mail Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return.That’s it. There’s nothing more to do except, of course, make that payment. Don’t Automatically File A Zero ExtensionThe IRS expects you to make a reasonable estimate of your tax liability when you file for the extension. That means taking a look at your income, withholding, and any major changes from last year, not simply plugging in zero and planning to deal with it later.(In some cases, in addition to penalties and interest, there’s also a risk that the extension itself could be challenged if the estimate on your extension isn’t reasonable. It’s not common, but the rule is on the books.)The better approach? Make your best good-faith estimate and send a payment with your extension request, even if it’s not the exact right amount. If you overpay, you’ll get a refund. If you underpay, at least you’ve reduced the amount subject to penalties and interest.Changes to the Mailbox RuleThere’s also a new twist this filing season that’s worth keeping in mind, especially if you’re thinking about mailing your extension at the last minute.For years, taxpayers have relied on the “mailbox rule,” which treats a return or payment as filed on the date of the postmark, not the date the IRS receives it. That’s what made it feel safe to drop your return in the mail on April 15 and call it a day. But now, the U.S. Postal Service has clarified that most postmarks reflect when mail is processed, not when it’s dropped in the mailbox. That means a piece of mail sent on April 15 might not be postmarked until April 16 or later. If that happens, your extension could be treated as late.If you mail your extension, consider going to the post office counter to get proof of mailing—such as a manual postmark or a certified mail receipt—instead of relying on a mailbox drop. You can also use a private delivery service (like FedEx or UPS) so long as you file on time and use the proper address (remember that many private delivery services will not deliver to a P.O. Box so check the instructions to find out the best address for your return).You Don’t Have to Have a ReasonIf you follow those rules, your filing extension is granted automatically. So why might you need an extension?Employers are generally required to send employees Forms W-2 and other wage statements by January 31, 2026. However, some forms, such as Forms 1042-S and certain Forms 5498, might not arrive until much later. There are many reasons you might not have received a form yet—you could be a beneficiary of a trust or estate, or a shareholder or partner in a pass-through entity, which means that associated Schedules K-1 might not be available yet. Additionally, if you're funding an IRA (you have until Tax Day), you may need to include that information on your Form 1040. Making that contribution can help you save for retirement, and may result in a tax break. However, patience is key since underfunding could cause you to miss out on tax benefits, while overfunding might lead to a penalty.You might need some time to review your tax return. Too often, we’re just rushing from one task to the next, but it is smart to take the time to carefully scan your return and look for omissions or errors. This holds true even if a tax professional prepared your returns. If you receive the returns a few days before the deadline, there’s usually no benefit in rushing them out the door.In some years, your return is simply more complicated than others. Not sure if you’ve included all of those crypto transactions? Sold your house and not sure about the basis? Forgot that you inherited an IRA? So many things can happen in any given tax year that differ from the previous year. Taking the time to run down the list of what you should have included can help avoid a nasty penalty later. And what if you want to discuss your returns with your tax preparer? Most professionals won’t have the time for a lengthy sit-down around Tax Day. Taking time later to review returns for completeness and to ask questions about any items you may not understand can pay off down the line.Or what if you’re just not ready? Maybe your receipts are still in boxes. Maybe you haven’t been well. Maybe your kid is graduating from college, and you’ve just been overwhelmed. Sometimes, life gets in the way. The IRS understands that there are reasons why you may need more time to file. But whatever your reason for not being ready to file, you can keep it private. You don’t need to tell anyone—even the IRS—why. It’s a no-questions-asked form, and the extension is granted automatically if you follow the rules.Automatic Extensions Some taxpayers automatically receive an extension of time to file without having to request it at all. Those include:If you’re a U.S. citizen or resident and you live outside of the U.S. or Puerto Rico, and your main place of business or post of duty is outside of the U.S. or Puerto Rico, or if you are active duty military and live outside of the U.S., you qualify for a two-month extension without having to file Form 4868. That moves your due date to June 15 for filing. However, interest is still due on any tax payment made after April 15.Members of the military and others serving in combat zones or hazardous zone areas generally have until at least 180 days after they leave the zone to file returns and to pay any taxes due. Taxpayers affected by natural disasters may have extra time. For more details or to see if you’re eligible, check the disaster page on the IRS website.Don’t Forget To Follow-Up Extensions are an incredibly useful tool for taxpayers. They give you time to get your return right, which is almost always better than rushing to meet a deadline.But extensions are not a completely free pass. Don’t just file for an extension and start rushing again in October. Take the extra time to get organized, gather your documents, and reach out for professional help if you need it.ForbesFiling For A Tax Return Extension? Don’t Make This Common MistakeBy Kelly Phillips ErbForbesForbes Last Minute Tax Guide: How To Navigate The Changes On Your 2025 ReturnBy Kelly Phillips ErbForbes11 Common Tax Filing Mistakes And How To Avoid ThemBy Kelly Phillips Erb