Your Business Filed an Extension. Is Your Personal Return Still Due?

Yes, unless you extended it separately. When your partnership or S corporation filed Form 7004, that extension covered only the business's own return. Your Form 1040 needed its own extension, requested by April 15, 2026, with Form 4868 or an electronic payment marked as an extension payment. If you got that extension, your 2025 return is due October 15, 2026. If you didn't, it was due April 15 and is now late.

Imagine that your business tax return and your personal tax return are like two separate items on your tax to-do list. If you apply for an extension for one of them, the other one remains exactly as it is, and the extension for the business doesn’t carry over to your 1040. Therefore, when a bookkeeper or a co-owner says to you that “we’ve filed the extension,” the right question to ask is which return they are referring to. Information on how the business side works, including details about which entities file Form 7004, is provided in our guide on how business tax extensions and Form 7004 work.

Expert Insight

Andrew Walsh, CPA, CFP®, CTFA
CPA, CFP CTFA & Tax Content Specialist

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Sometimes K1’s will be late through no fault of your own. If you are in this situation, with the October 15th deadline approaching, try to get as accurate information as you can and file by the extended deadline. Then work to get the finalized K1 records from the business. It is easier to pay penalties and interest on a change in balance due for the amended return once the final K1 is ready than not filing at all and adding a failure to file penalty on top of all this.

This Matters Most If You Receive a Schedule K-1

The type of tax situation explained on this page affects partners, the shareholders of an S corporation, and the members of a limited liability company that is taxed as a partnership or an S corporation, since each of them has an interest in a pass-through business. In all these cases the business prepares its own return, either Form 1065 or Form 1120-S. It then sends you a Schedule K-1 indicating your share of its income, deductions and credits, as you need this information in order to complete your own 1040.

Whether you run the business as a sole proprietorship or as a single-member LLC, you will not have to file a separate federal income tax return for the business. The business’s income is included on Schedule C of your Form 1040. The only extension that matters in this situation is the one you apply for on your personal tax return. A C corporation does file its own return and can also apply for an extension, but it pays its own taxes and does not send you a K-1, so its extension and yours are simply two separate extensions.

Your Deadline Sits Next to Your Business’s Deadline

For calendar-year filers, the tax year 2025 dates line up like this:

March 15, 2026 fell on a Sunday, which is the reason why the business returns were due on Monday, March 16.

The business has to send you your K-1 by the day its return is due. In this case, when the business applied for an extension, the due date was changed from March 16 to September 15, 2026, so there were roughly 30 days between the date of the K-1 and your own October 15 deadline. To put it simply, the extension obtained by the business did not provide you with any additional time; instead, it consumed most of the time that had been given to you by your own extension.

If You Extended Your Personal Return

If you had asked for the extension by April 15, 2026, either by using Form 4868 or by making a designated electronic payment, your tax return for 2025 is due on October 15, 2026. The K-1 should have been sent to you by September 15. The sensible thing to do at this point is to complete the return well in advance of the deadline rather than waiting until the last day, since any figure that is found to be incorrect will require time to be corrected.

A late K-1 won’t affect your October 15 deadline; if it hasn’t reached you yet, our guide explains what to do if your K-1 hasn’t arrived.

If You Didn’t Extend Your Personal Return

If you had thought that the business’s extension applied to you, then that is your situation. Your return was due on April 15, 2026, and so long as you haven’t filed it the IRS will regard it as being late. A failure-to-file penalty of 5% per month or part of a month applies to any unpaid tax, but in no case will the penalty exceed 25%. When both penalties run in the same month, the IRS reduces the failure-to-file penalty to 4.5% and charges the 0.5% late-payment penalty alongside it.

A return filed more than 60 days late also carries a minimum failure-to-file penalty. For a 2025 return, that minimum is $525 or 100% of the underpayment, whichever is less. The IRS will also charge interest on the unpaid amount until it has been paid.

File as soon as possible, using the K-1 forms that you have; our guide on what happens when you file your 2025 return late explains the penalties and also how to file after the deadline.

Your Tax Was Due in April Either Way

An extension will postpone the date on which you have to file your return but will not alter the date on which the tax was due, as the instructions for both Form 4868 and Form 7004 state. A partnership does not pay federal income tax by itself, and an S corporation usually does not either. Therefore, the tax on your share of their income is included on your individual 1040, and that tax was due on April 15, 2026.

If you still have some amount to pay, you can pay it now. Interest will be charged on any remaining unpaid tax at a rate of 7% from October 1 through December 31, 2026, compounded daily. The IRS adjusts this rate every quarter (IR-2026-98), and in addition, a late-payment penalty equal to ½% of the unpaid tax for each month may also apply. Our article on penalties and payment plans if you can’t pay in full outlines the different options available to you.

A Checklist for Owners Before October 15, 2026

• To find your extension record, look for the acknowledgment of an e-filed Form 4868, your copy of a paper one, or the confirmation number for a payment that you have designated as an extension payment.
• Do not treat the business’s Form 7004 as your extension.
• Make sure that you have a K-1 form from each partnership or S corporation of which you own a share.
• Pay the balance you still owe for 2025.
• File by October 15, 2026 if you extended, or as soon as possible if you didn’t.
• Keep the confirmations with your 2025 tax records.

Expert Insight

Lea Uradu, JD
Tax Content Reviewer

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Every fall, we hear from business owners who are caught off guard when they realize their company’s extension didn’t protect their individual return. An entity’s Form 7004 extension buys time for the business books, but it leaves your personal 1040 completely vulnerable unless Form 4868 was also filed by April 15. If your K-1 arrives late in September, the best approach is to drop everything and get the return filed immediately to stop compounding interest and penalty accrual in its tracks.

Finish Your Return Before October 15

If you have your K-1 form and want to complete your return by yourself before October 15, 2026, then you can prepare and e-file it online. For information about deadlines, penalties and the next steps in every extension situation, see Tax Extension Help.

File your 2025 return yourself with FileTax.com