Business Tax Return Due Dates and Extensions

Business tax returns do not all share the same due date. The date depends on how the business is taxed.

Due dates for a calendar-year business

• Partnerships and multi-member LLCs taxed as partnerships (Form 1065): the 15th day of the third month after the end of the tax year, which is March 15 for a calendar year.
• S corporations (Form 1120-S): also March 15 for a calendar year.
• C corporations (Form 1120): the 15th day of the fourth month, which is April 15 for a calendar year.
• Sole proprietors and single-member LLCs (Schedule C): the business is reported on the owner's personal return, which is generally due April 15.

When a due date falls on a weekend or a legal holiday, it moves to the next business day. Businesses with a fiscal year that does not end in December have different dates.

What an extension does

Filing an extension (Form 7004 for most business returns) gives you more time to file. It does not give you more time to pay. If the business owes tax, an estimate of it is still due by the original date, and interest and penalties can apply to what is paid late.

For partnerships and S corporations, the extension generally adds six months. K-1s go to the owners later too, which can delay the owners' own personal returns, so it is worth thinking about the owners' deadlines before you decide to extend.

Why filing late costs more than you might think

S corporations and partnerships can be charged a late-filing penalty for each month and each owner, even when no tax is owed, because the return is the document that tells each owner what to report. This is one reason the extension is worth filing if you cannot meet the deadline.

State deadlines are separate

States have their own business returns and reports, and their dates do not always match the federal ones. Texas, for example, has an annual franchise tax report generally due May 15. Check the dates for each state where the business operates.

A simple habit that helps

Keep your bookkeeping current during the year. A return is much easier to prepare and file on time when the books are already reconciled, and an extension then becomes a choice rather than a necessity.

Dates and rules change, and your situation may have special rules. If you are unsure which date applies to your business, ask before the deadline, not after.