Key takeaways

• Taxpayers facing the Oct. 15 extension deadline can prepare by gathering income forms, deduction records, payment history, and prior returns.
• A tax extension provides more time to file, not more time to pay. Unpaid taxes may be subject to interest and penalties.
• Before filing, taxpayers should check for mistakes, confirm filing status, review payments, and verify personal and banking information.

An estimated 18 million Americans file for a tax extension each year, according to IRS data, amounting to about 13% of filers.¹

If you’ve already filed a tax extension for your 2025 return, the new deadline to complete and submit your return is approaching: Oct. 15 marks the end of the standard six-month extension.

As the deadline approaches, here’s what you need to finish up your tax returns.

Gather tax materials

A federal tax return submitted after April 15 doesn’t need anything different than if you had filed before the standard deadline. As part of a good tax preparation checklist, you should check that you have these essential documents before getting started:

• Income information like W-2 forms, company paystubs, and 1099 forms
• Any notices you’ve received from the IRS
• Relevant receipts and documentation to verify tax deductions and/or tax credits you plan to take
• Last year’s return, as a reference for personal information and prior-year tax details
• Confirmations of any IRS payments

Another notable item to have available is your estimated tax payment history. If you’ve made estimated tax payments, be prepared with those receipts.

Because the U.S. tax system is a “pay as you go” arrangement, people typically pay taxes during the year as they earn income. However, if you pay too little tax along the way, you can be penalized for underpayment.²

For those with predictable income, tax being withheld from paychecks can help meet the IRS-recommended threshold of paying 90% of your tax owed for the current year.³ If you end up falling below that limit, that’s when interest and penalties can trigger.

That’s where estimated tax payments can better align taxes paid with taxes owed. If you don’t expect to meet that threshold, or if you have other sources of income (such as from side hustles or additional jobs) that aren’t subject to sufficient withholding, making estimated tax payments directly to the IRS could keep your potential tax burden in check.

Decide how to file your taxes

Determine your filing status

Picking which status you’ll use to file your taxes is a good place to start your return. Tax bracket thresholds and deduction amounts changed for 2025 and 2026, so it’s worth reviewing which status best applies to your situation.

Around half of federal taxpayers were part of a married joint return as of 2022. Filing a tax return jointly can be one of the tax benefits of marriage. Single filers make up another 37% of taxpayers.⁴

For people with dependents or more complex tax situations, filing as “head of household” could allow access to a higher standard deduction and wider tax brackets, though there are strict eligibility requirements to qualify.

Read more: When filing as head of household makes sense

Filing options: Do-it-yourself, professional preparation

For filers with simpler returns or more experience with tax prep, a do-it-yourself option could be more direct way to get your taxes done before the extension deadline.

The IRS offers two Free File options for federal returns — a guided process for taxpayers with an Adjusted Gross Income (AGI) of $89,000 or below, or free fillable forms for people who are more comfortable doing the work themselves (and with no income limits).⁵

Others may have limited time to spend on their taxes before the Oct. 15 extension deadline, so seeking help from a tax professional could make sense. More than half of 2024 returns were filed by a paid practitioner — meaning someone other than the taxpayer.⁶

Those who feel more at ease discussing financial questions in person could benefit from working locally with a tax professional, while tax software and online services also offer different levels of support from a certified public accountant (CPA) or other tax professionals.

Understand any extra charges you could owe

While you may have received extra time to prepare your federal tax return, the amount of tax itself still needs to have been paid by April 15. Filers expecting a refund generally don’t have extra steps to take, while those who think they owe taxes and haven’t paid in full should understand how additional charges can add up.

Filers still have to pay any tax owed even if they didn’t submit a return by the April deadline. Ideally, taxpayers who submitted Form 4868 for the initial tax extension should have estimated how much they’d owe and paid that amount at the same time.

For those who didn’t include any payment with their extension paperwork, estimate what you owe as soon as possible and make a payment based on that estimate.

The sooner you pay the tax, the less you’ll accumulate in interest and penalties, including a late payment penalty that’s assessed monthly.⁷ Even if you decide to file your return closer to Oct. 15, you can limit extra charges if you pay the tax before that date.

People who may not be able to pay the full amount at once could see if they qualify for one of the IRS’ “simple payment plans,” which have eligibility limits based on how much is owed. Another option is submitting an “offer in compromise,” which allows qualifying taxpayers to settle with the IRS for less than the full amount of tax due under certain circumstances.^8,9

Double-check your personal information

Accurate and updated personal information is essential to a successful tax filing. The IRS could notify you that your tax return was rejected if you mistakenly enter the wrong personal information for yourself, your spouse, or dependents, such as Social Security numbers. If another taxpayer could claim one of your dependents, verify that no one else has filed using their information before turning to your own return.¹⁰

People hoping for a tax refund should make any necessary updates to banking information. Nearly all (98%) of tax year 2025 refunds as of mid-March were issued to taxpayers through direct deposit.¹¹ Verifying account and routing numbers helps avoid receiving a CP53E notice, which gives people only 30 days to correct their payment information.¹²

Keep up with taxes year-round

Using a tax extension wisely can give filers some breathing room on a financial task that can be stressful. According to Empower data, 37% of Gen Z doesn’t feel confident about filing their taxes.

Using strategies such as tax-advantaged retirement savings and checking in on withholdings can help people keep up with taxes throughout the calendar year, so it can feel like less of a scramble at filing time.