LLC Tax Filing Deadlines You Cannot Miss
Miss a tax deadline and the IRS charges you for the privilege. Interest, penalties, and a growing stack of notices follow, all because a date slipped past.
LLC owners miss deadlines more often than most, because an LLC does not have one fixed tax deadline. The date depends on how your LLC is taxed.
This guide covers every federal deadline that matters for LLC owners: March 15 is the deadline that surprises the most LLC owners, and it applies to partnerships and S corps, not the April 15 date everyone expects. Learn which dates apply to your LLC and you will never pay a late penalty again.
Why LLC Deadlines Are Confusing
An LLC is a legal entity created by the state, but the IRS does not have an “LLC” tax category. By default, a single-member LLC is taxed as a disregarded entity and a multi-member LLC is taxed as a partnership.
Either type can also elect S corp or C corp taxation. Each classification files different forms on different dates.
That is why generic tax advice fails LLC owners. The right deadline for your business depends on an election you may have made years ago and forgotten. If you are unsure how your LLC is taxed, start with our guide on how LLCs are taxed before circling dates on the calendar.
The Two Big Filing Deadlines
March 15 is the deadline for LLCs taxed as partnerships (Form 1065) and LLCs that elected S corp status (Form 1120-S). Both forms report the business’s income and pass it through to the owners on Schedule K-1. If March 15 falls on a weekend or holiday, the deadline moves to the next business day.
April 15 is the deadline for individual returns, which is where single-member LLCs report their business income on Schedule C of Form 1040. It is also the deadline for the first quarterly estimated tax payment, which is why April 15 feels like the busiest tax day of the year for small business owners.
Deadlines for Single-Member LLCs
A single-member LLC with default taxation reports business profit and loss on Schedule C, filed with the owner’s personal Form 1040 by April 15. There is no separate business return. Our walkthrough of single-member LLC taxes covers exactly what goes on that Schedule C.
If April 15 is impossible, file Form 4868 for an automatic six-month extension to October 15. The extension covers filing only, not payment. Estimate what you owe and pay it by April 15, or interest and penalties accrue on the balance while you wait.
Deadlines for Multi-Member LLCs
A multi-member LLC taxed as a partnership files Form 1065 by March 15. The partnership itself pays no income tax; the return exists to report income and issue Schedule K-1 forms to each member. Members then report their share on their personal returns by April 15.
The March 15 deadline bites because K-1s must reach members in time for them to file by April 15. A late partnership return cascades into late personal returns for every member. File Form 7004 by March 15 for an automatic six-month extension to September 15 if you need more time.
Deadlines for LLCs Taxed as S Corps
An LLC that elected S corp taxation files Form 1120-S by March 15 and issues K-1s to its shareholders. Like partnerships, the S corp pays no federal income tax itself; income flows to the owners’ personal returns.
Watch the election deadline too. To have S corp status effective for the current tax year, Form 2553 generally must be filed within two months and 15 days of the start of the tax year, which means March 15 for a calendar-year LLC.
Miss it and the election takes effect the following year. The IRS explains the rules on its S corporations page.
Quarterly Estimated Tax Dates
LLC owners usually pay tax in four installments during the year, not one lump sum in April. The federal due dates are April 15, June 15, September 15, and January 15 of the following year. These apply to owners of pass-through LLCs whose withholding does not cover their tax bill.
Skipping quarterlies and paying everything in April triggers an underpayment penalty, even if you pay the full amount on time. The IRS wants its money as you earn it. Mark all four dates now; they are the most commonly missed deadlines in small business.
Do Not Forget State Deadlines
States set their own income tax deadlines, annual report due dates, and franchise tax payments, and they do not always match the federal calendar. Some states require quarterly estimates on a different schedule.
A few states have no income tax at all, which simplifies the calendar but changes nothing about the federal dates or your annual report. Check your state’s revenue department site every year, because states change dates and forms without much fanfare.
Your LLC may also need an Employer Identification Number before certain deadlines apply. If you have not gotten one yet, our guide on how to get an EIN for your LLC walks through the free IRS application.
Build a Deadline System That Runs Itself
Put every applicable date in your calendar right now, each with a reminder two weeks out. The filing deadline, the four estimated payment dates, and your state’s annual report deadline all go in. Two weeks of lead time is enough to gather documents without panic.
Keep your books current every month, not every April. The founders who miss deadlines are usually the ones reconstructing a year of transactions in March. Thirty minutes of bookkeeping a month turns tax season into a non-event.
Consider filing extensions as insurance, not as a plan. Submitting Form 7004 or 4868 early costs nothing and protects you if life intervenes. Just remember the golden rule: the extension covers the paperwork, never the payment.
Finally, review your tax classification once a year with your CPA. Businesses outgrow their default status, and an election made at the wrong time can create a surprise deadline. A fifteen-minute annual review keeps the calendar matched to reality.
What Happens If You Miss a Deadline
The failure-to-file penalty is generally 5% of unpaid tax per month, capped at 25%. The failure-to-pay penalty is 0.5% per month, also capped at 25%. Interest compounds on top of both.
For partnership and S corp returns, the IRS also charges a per-partner, per-month penalty for late filing, which gets expensive fast for multi-member LLCs.
If you have already missed one, file as soon as possible. Penalties accrue monthly, so every week you wait costs money. In many cases the IRS will abate first-time penalties if you ask and have a clean compliance history.
Frequently Asked Questions
When are LLC taxes due?
It depends on tax classification. Single-member LLCs report on Schedule C by April 15. Multi-member LLCs file Form 1065 by March 15.
LLCs taxed as S corps file Form 1120-S by March 15. Quarterly estimated payments are due April 15, June 15, September 15, and January 15.
What is the March 15 deadline for LLCs?
March 15 is the filing deadline for partnership returns (Form 1065) and S corp returns (Form 1120-S). It is also the general deadline for electing S corp status for the current year via Form 2553. An extension to September 15 is available with Form 7004.
Does an extension give me more time to pay?
No. Extensions extend the filing deadline only. You must still pay what you estimate owing by the original deadline, or interest and late-payment penalties apply to the balance.
Do single-member LLCs file a separate tax return?
No. By default, a single-member LLC is a disregarded entity and its owner reports business income on Schedule C of Form 1040. The IRS has more detail on its limited liability company page.
What if my LLC made no money this year?
You generally still must file the required return for your classification, even with zero income. Partnerships and S corps file their information returns regardless, and single-member LLCs report the activity (or lack of it) on Schedule C.
