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TL;DR:
For US companies with a calendar year-end (Dec 31), the main federal tax deadlines are March 15 for S-Corps and Partnerships (Form 1065), and April 15 for C-Corps (Form 1120). Filing an extension (Form 7004) pushes the filing deadline six months, but not the payment deadline.
Direct Question Answer
What is this about? A guide to the key annual tax filing deadlines for US businesses. Who is it for? All founders of US LLCs and C-Corps. When is it relevant? Annually, as these are fixed dates that every business must adhere to in order to avoid penalties.
Decision Summary
Who should act? All business owners must be aware of and meet these deadlines. Who can ignore? No one. Missing these deadlines results in automatic IRS penalties for failure to file.
For business owners, "tax season" isn't just a single day in April. It's a series of critical deadlines that vary based on your company's legal structure. Understanding and meeting these deadlines is a fundamental aspect of US tax compliance. The IRS imposes automatic penalties for late filings, so marking these dates on your calendar is essential for avoiding unnecessary costs.
This guide assumes your business uses a calendar year-end (December 31), which is the case for the vast majority of companies.
Key Federal Tax Filing Deadlines
March 15
Partnerships & S-Corps
This is the deadline for entities that 'pass through' their income to their owners.
April 15
C-Corporations & Individuals
This is the main deadline for corporations that pay their own tax, as well as for individual tax returns.
Note for Foreign-Owned LLCs: A single-member LLC owned by a non-resident is a "disregarded entity" but has special reporting requirements. It must file Form 5472 with a pro-forma Form 1120. This filing is due on **April 15**.
Filing an Extension: Form 7004
What if you need more time? The IRS allows you to file for an automatic six-month extension to file your return. This is done by submitting Form 7004 on or before the original due date.
Crucial Point: An Extension to File is NOT an Extension to Pay.
Even if you file an extension, you are still required to estimate your tax liability and pay that amount by the original due date (April 15 for C-Corps). Failure to do so will result in late payment penalties and interest.
Extended Deadlines:
- S-Corps & Partnerships: The extended deadline is **September 15**.
- C-Corps & Foreign-Owned SMLLCs: The extended deadline is **October 15**.
State Tax Deadlines
On top of federal deadlines, you must also be aware of your state-level obligations. These vary widely:
- State Income Tax: Many states have their own corporate income tax returns with deadlines that often, but not always, align with federal dates.
- Franchise Tax: States like Delaware have a separate Franchise Tax with a different deadline (March 1 for Delaware C-Corps). This is a tax for the privilege of being incorporated in the state and is due even with no business activity.
- Annual Reports: Most states require an Annual Report filing to keep your company's information current. These have their own unique deadlines throughout the year based on your incorporation date.
Tracking this patchwork of deadlines is one of the key benefits of an annual compliance service.
Never Miss a Deadline Again
For a founder, managing these multiple deadlines while trying to build a business is a recipe for missed filings and unnecessary penalties. YourLegal's Vitals and Elite plans are designed to take this entire burden off your shoulders. We track all your federal and state deadlines, prepare the filings, and ensure everything is submitted on time, every time.