Business tax deadline 2025: when are business taxes due?

As the expression goes, “nothing is certain but death and taxes.” Everyone knows you have to pay the IRS when you earn an income, but not just individually. Companies, whether giant corporations or sole proprietorships, have to pay taxes — and they have to do it on time. So, when are business taxes due?

When you start a business, one of the things you will have to deal with is deadlines.

Your clients will not accept getting what they paid for whenever you get around to finishing it. You set expectations for when your client will receive your goods or services, and you deliver on time. If you don’t, you risk getting a reputation that you are difficult to deal with, and will likely leave your client in a bad spot.

The same holds true for taxes.

There are certain deadlines you need to meet for federal taxes, and there are fines and penalties you could be charged if you don’t. Let’s take a look at some of the income tax due dates you might need to know as a business owner.

Disclaimer: This content should not be construed as legal or tax advice. Always consult an attorney or tax professional regarding your specific legal or tax situation.

Small business tax deadlines

When entrepreneurs look to start a business, taxes may not be top of mind at the outset. But keeping tax dates organized can be a big help for small businesses to avoid the end of year scramble. 

To get an idea of what payments are collected by the IRS from businesses on a month-to-month basis, take a look at its tax calendar. Then, start to determine what you might personally owe and when based on the type of business you own. 

• S corps, partnerships and LLCs taxed as partnerships - March 17, 2025
• C corporations and sole proprietorships - April 15, 2025
• Quarterly tax payments: Jan. 15, April 15, June 16, and Sept. 15, 2025

Bear in mind that holidays and weekends can affect various filing dates throughout the year, so always refer to IRS.gov to verify if your tax deadline falls outside of the business week.

1. Tax deadline for sole proprietorship 

If you are working independently and have not been set up as an LLC with the IRS, you are a sole proprietor. Your income taxes will be designated on Schedule C of your individual Form 1040, and your self-employment taxes will be calculated on Schedule SE (see this guide for more on self-employment taxes). In addition to filing your income tax return, you might need to pay estimated quarterly payments.

So, when are business taxes due for sole proprietors? If you operate on a fiscal year it is due the 15th of the fourth month following the end of the tax year. 

For those who operate on a calendar year, here are the important dates you need to keep in mind as the sole proprietor of your business:

• April 15th:If you pay estimated taxes for the current year, the first installment will also need to be paid at this time.
• June 15th: The second installment payment of estimated taxes is due.
• September 15th: The third installment of estimated taxes is due. In addition, if you filed an extension for your 1040, the final return for the year is due.
• January 15th: The final installment of your estimated taxes is due.

2. Tax deadline for partnerships

If you are co-owner of a business with someone else, you need to file Form 1065 to report your taxes.This return is due on March 15th for those operating on a calendar year. Otherwise, it’s due on the 15th day of the third month. 

Both partners will need to keep a copy of Schedule K-1, which shows each person’s share of the income and which items are reported on his or her individual return. Keep in mind that estimated taxes are not paid by the business itself, but by both partners independently.

3. Tax deadline for Limited Liability Company (LLC)  

If you are working on your own and have registered as a Limited Liability Company with the IRS, your income and expenses will be recorded on Schedule C of your individual 1040, and your self-employment taxes will be calculated on Schedule SE, just as they would be for a sole proprietor.

The return is due April 15th, and your quarterly estimated tax payments must be submitted by April 15th, June 15th, September 15th and January 15th for the current year.

LLCs may request an extension to Sept. 15, 2025, by filing Form 7004.

4. Tax deadlines for C corps

For C corps, there are a couple of deadlines to be aware of:

• April 15, 2025 - Deadline to file Form 1120, U.S. Corporation Income Tax Return
• October 15, 2025 - Deadline for extended C corp returns.

These deadlines are for businesses that follow a calendar year. If your business uses a fiscal year, your return needs to be filed by the 15th day of the fourth month following the close of your tax year.

Additional situations could apply. IRS Publication 542 includes additional tax-related information for corporations.

5. Tax deadline for S corps

If you file as an S corporation, your taxes are due on the 15th day of the third month following either the end of the calendar or fiscal year, whichever your business follows.

Either way, domestic corporations will need to file Form 1120-S, U.S. Income Tax Return for an S Corporation to report income gains, losses, deductions. More information is available on the government website.

You’ll want to take note that different deadlines apply if filing by mail or electronically. 

• To file by mail in 2025, a corporation must have filed Form 3021 by Feb. 28, 2024.
• To file electronically in 2025, a corporation must have filed Form 3921 by April 1, 2024. You’ll need to request a TCC first to obtain permission from the IRS to do so. It can take weeks to receive the code needed to set up your account with the IRS Filing Information Returns Electronically (FIRE), so plan ahead.

Request a tax deadline extension  

When it comes to tax season, sometimes a tax deadline extension is needed. Let’s take a look at how an extension request works. 

What happens if you miss the business tax deadline?

If you miss a deadline for filing taxes, all is not lost. Here is a quick breakdown of the dates to be aware of if you’ve missed a deadline based on your business type:

• March 15, 2025: If your business is a partnership, S corp, or LLC taxed as a partnership, you’ll need to file a Form 7004 by this date to request an extension.
• April 15, 2025: Businesses that include C corps and sole proprietors will need to instead file a Form 4868 by this date for an extension.

To avoid being assessed penalty fees and accruing interest, however, taxes still must be paid by the deadline. If you aren’t able to pay the full amount you believe is due on or before the deadline, consider requesting an installment payment plan. 

Making payments over time can reduce the total amount of interest that you might otherwise be assessed including a 5% penalty on the remainder of unpaid taxes each month up to 25% until you file your return. Monthly penalty fees can cost you another 0.5% until your taxes have been paid in full, also up to 25%.

Tax tips

Now that you know when business taxes are due, it’s important to learn how to avoid penalties by submitting them correctly. Hereare a few tips to help your business meet filing deadlines and prepare tax returns without any hitches. These include:

• Include all forms: Make sure that when you send in your tax forms, you include all of the related forms and schedules. This will help you to steer clear of late-filing penalties.

• Talk to your accountant early: Give yourself time to pull together everything far enough ahead of time to make it less likely you’ll make last-minute mistakes due to being rushed. Review all the figures before filing. Being a stickler for accuracy can help you avoid penalties, additional taxes (due to deductions being missed), or a time-consuming audit.
• File for an extension when needed: An extension (see above) will give you additional time to get everything done correctly. Keep in mind, however, that you will still have to pay any taxes that were owed on the original return due date, even if you file an extension.
• Review last year’s return: This can act as a guide for all the information you need in the current year.

Plan ahead before taxes are due 

Below are some simple ways to plan ahead for your tax due dates so you do not disrupt the flow of your business’s operations when deadlines hit:

• Know when the dates for filing taxes are due. Noting the due dates for the year in advance will help you set a schedule. Mark them on your calendar and formulate a plan for making sure you are ready when they come around.
• Complete bank reconciliations. While this might sound strange, ensuring your reconciliations are complete before the tax due dates will keep your accounting records up to date and all items of income and potential deductions recorded for when you need to know them. Here are a few tips to make sure your financials are ready for year-end.
• Set up a meeting in December with your accountant. This will allow you to create a plan of attack and give you and your accountant a chance to discuss potential problem areas.

Knowing when business taxes are due is an important step in being proactive about planning your returns and payments. Talk to your Certified Public Accountant (CPA) about the deadlines for your type of company and formulate a schedule so you consistently file everything on time.