When an LLC pays taxes depends on how the IRS classifies it. A single-member LLC files and pays with the owner’s personal Form 1040 by April 15. A multi-member LLC files a partnership return on Form 1065 by March 15, and each member then pays personal tax on their share by April 15. An LLC that elected S-corporation status files by March 15; one that elected C-corporation status files and pays by April 15. On top of the annual return, nearly every LLC owner sends quarterly estimated payments to the IRS in April, June, September, and January.
Which of those calendars is yours comes down to a single question: has the LLC filed an election form with the IRS? If not, the default rules apply. One owner means disregarded-entity treatment. Two or more owners means partnership treatment. Filing Form 8832 moves the LLC to C-corporation treatment; filing Form 2553 moves it to S-corporation treatment.1Internal Revenue Service. About Form 8832, Entity Classification Election2Internal Revenue Service. About Form 2553, Election by a Small Business Corporation
Single-Member LLC: April 15
Because the IRS treats a single-member LLC as an extension of you personally, business income goes on your Form 1040 through Schedule C (or Schedule E for rentals, Schedule F for farming).3Internal Revenue Service. Single Member Limited Liability Companies Both filing and payment are due April 15. For the 2025 tax year, that is April 15, 2026.4Internal Revenue Service. When to File
Filing Form 4868 before April 15 gives you an automatic six-month extension to October 15.5Internal Revenue Service. Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return The extension covers paperwork, not payment. Any tax you owe is still due April 15, and interest starts running the next day on anything unpaid.
Miss April 15 without an extension and the failure-to-file penalty is 5% of the unpaid tax for each month or part of a month the return is late, capped at 25%.6Internal Revenue Service. Failure to File Penalty Interest on the unpaid balance runs on top of that.
Multi-Member LLC: March 15, Then April 15
A multi-member LLC defaults to partnership treatment, which splits filing into two steps. The LLC files Form 1065 by March 15, then issues each member a Schedule K-1. Each member reports the K-1 figures on their personal Form 1040 by April 15.7Internal Revenue Service. LLC Filing as a Corporation or Partnership For 2026, March 15 lands on a Sunday, so the Form 1065 deadline shifts to March 16.8Internal Revenue Service. Publication 509, Tax Calendars
The LLC itself pays no income tax with Form 1065. Filing Form 7004 by the due date grants an automatic six-month extension to September 15.9Internal Revenue Service. Instructions for Form 7004 Members who are still waiting on a K-1 will usually need to extend their personal returns as well.
Late filing of Form 1065 is expensive even though no tax is due with it. For returns due after December 31, 2025, the penalty is $255 per partner for each month or part of a month the return is late, up to 12 months.6Internal Revenue Service. Failure to File Penalty A five-member LLC filing three months late owes $3,825 in penalties before any tax question is even raised.
LLCs Taxed as Corporations
S-Corporation Election
An LLC that filed Form 2553 files Form 1120-S by March 15 (March 16 in 2026).10Internal Revenue Service. Instructions for Form 1120-S (2025) Like a partnership, the S-corporation generally pays no income tax at the entity level; income flows to shareholders through Schedule K-1, and each shareholder reports it on their personal return by April 15. Form 7004 buys another six months to file.9Internal Revenue Service. Instructions for Form 7004 Late-filing penalties mirror the partnership structure: a per-shareholder, per-month charge.
C-Corporation Election
An LLC taxed as a C-corporation files Form 1120 by April 15 for calendar-year filers, and the LLC itself pays the tax at that time. If the LLC uses a fiscal year rather than a calendar year, Form 1120 is due the 15th day of the fourth month after the fiscal year closes.11Internal Revenue Service. Starting or Ending a Business
Quarterly Estimated Payments
Federal income tax runs on a pay-as-you-go schedule. If your LLC is a pass-through entity, nothing is withheld for you, so you send the IRS four estimated payments a year covering both income tax and the 15.3% self-employment tax (12.4% Social Security plus 2.9% Medicare).12Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
For calendar-year filers, the four dates are:13Internal Revenue Service. When to Pay Estimated Tax
- Q1 (January through March): April 15
- Q2 (April through May): June 15
- Q3 (June through August): September 15
- Q4 (September through December): January 15 of the following year
If a date falls on a weekend or legal holiday, the deadline moves to the next business day. All four 2026 dates fall on weekdays.
You can avoid an underpayment penalty by meeting any one of three safe harbors: owing less than $1,000 after withholding and credits, paying at least 90% of the current year’s tax, or paying at least 100% of the prior year’s tax.14Internal Revenue Service. Estimated Taxes Higher earners face a stricter rule. If your adjusted gross income was over $150,000 last year ($75,000 if married filing separately), the prior-year safe harbor jumps to 110%.15Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty A growing LLC can cross that threshold without the owner adjusting quarterly payments, which is a common way to end up with a penalty despite paying “the same as last year.”
Payroll and Excise Deadlines
Hiring employees adds a separate calendar that runs regardless of income tax classification.
Form 941 reports withheld income tax and both shares of Social Security and Medicare. Each quarter’s return is due the last day of the month after the quarter ends:16Internal Revenue Service. Instructions for Form 941 (03/2026)
- Q1: April 30
- Q2: July 31
- Q3: October 31
- Q4: January 31
Federal unemployment tax goes on Form 940, due January 31 of the following year, with 10 extra calendar days if you deposited all FUTA on time during the year.17Internal Revenue Service. Employment Tax Due Dates Quarterly FUTA deposits are required whenever cumulative liability passes $500.18Internal Revenue Service. Depositing and Reporting Employment Taxes
LLCs dealing in fuel, air transportation, indoor tanning, or other regulated goods and services may also file Form 720 quarterly for federal excise tax.19Internal Revenue Service. Form 720, Quarterly Federal Excise Tax Return
Payroll obligations carry a personal risk the LLC shield does not cover. If the LLC fails to deposit withheld income tax or the employee share of Social Security and Medicare, the IRS can assess the trust fund recovery penalty against any owner or officer responsible for collecting and paying those taxes. The penalty equals the full unpaid trust fund amount, plus interest.20Internal Revenue Service. Trust Fund Recovery Penalty
State Deadlines
State obligations run on separate calendars and rarely line up with the federal ones. Three types come up most often.
Franchise Taxes and Annual Fees
Many states charge a franchise, privilege, or minimum business tax for the right to operate as an LLC in the state. Amounts range from nothing to $800 or more and may depend on revenue or membership. Due dates commonly fall on March 1, April 15, or the anniversary of the LLC’s formation. Missing a payment triggers late fees and can eventually lead to administrative dissolution.
Annual and Biennial Reports
Most states require a periodic report confirming address, registered agent, and member information. Fees run from $0 to roughly $800, with most well under $100. Some states collect the report every year, others every two. Skipping it can cost the LLC its good standing.
Sales and Use Tax
If your LLC sells taxable goods or services, most states require collection once you cross an economic nexus threshold, commonly $100,000 in sales or 200 transactions. Remittance schedules track volume: high-volume sellers often file monthly, moderate quarterly, low-volume annually. An LLC selling across multiple states can end up managing a dozen separate calendars.
Foreign-Owned Single-Member LLCs
A single-member LLC wholly owned by a foreign person or entity is not treated like a domestic disregarded entity for reporting. It must file a pro forma Form 1120 with Form 5472 attached, disclosing reportable transactions with foreign related parties.21Internal Revenue Service. Instructions for Form 5472 The deadline is April 15 for calendar-year filers.22Internal Revenue Service. Instructions for Form 1120 (2025)
The penalty for missing this filing is $25,000 per form. If the return remains unfiled 90 days after the IRS sends a notice, another $25,000 accrues for each additional 30-day period, with no cap.23Internal Revenue Service. International Information Reporting Penalties The requirement applies even when the LLC had almost no activity during the year.