2026 Business Tax Deadlines: Your Guide to This Tax Season
Navigating business tax deadlines can feel overwhelming – and missing a business tax deadline can be costly.
This guide breaks down the most important business tax deadlines, extensions, and estimated quarterly payments so business owners know exactly what’s due, when it’s due, and how to stay compliant.
Table of Contents:
- When are taxes due for businesses?
- Tax deadlines by business type
- Need more time? File a business tax extension
- If you're making estimated quarterly tax payments
- Filing taxes late or missing a deadline?
- If you're sending W-2s or 1099s
- Optimize your tax savings with Acuity
- 2025 business tax deadline FAQs
When are Taxes Due for Businesses?
There’s more than one business tax deadline – plus businesses can have different deadlines and requirements than individuals.
As a business owner, staying aware of tax filing deadlines is crucial to avoid penalties and fees. However, managing business taxes can be complicated, especially for newcomers.
Key Business Tax Deadlines for 2026
- March 16, 2026: S Corps, Partnerships, and LLCs taxed as partnerships
- April 15, 2026: C Corporations and Sole Proprietorships (This is also the individual income tax deadline.)
- Quarterly Tax Payments: January 15, April 15, June 15, September 15, 2026
If a due date falls on a weekend or legal holiday, the deadline moves to the next business day.
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Business Tax Deadlines by Entity Type
S Corps, Partnerships, & LLCs taxed as a partnership:
The first tax returns for the season are due March 16, 2026. This deadline applies to partnerships, LLCs that are taxed as a partnership, and S corp tax returns.
Not only will your business tax deadline change based on your business structure, but the way your business is taxed can vary, too.
Partnerships
Partnerships are a relatively simple structure which involves two or more people who share ownership of the business. A general partnership gives all parties equal financial, legal, and management responsibilities.
From a tax perspective, a partnership is a pass-through entity, meaning the business itself doesn’t pay federal income tax. Instead, the partners of the business report their income, deductions and credits on individual tax returns using Schedule K-1 (Form 1065).
Additionally, a partnership may have to pay self-employment taxes and estimated quarterly taxes, so we recommend speaking with a professional to learn more about your specific tax situation.
S Corporations
S corporations are one the two common types of corporations, next to C corps. Smaller groups and family companies typically fall under this category, and there are specific qualifications that a company must meet to be a S corp. S corps are also limited to 100 shareholders.
S corps utilize pass-through taxation, too, meaning the company’s income, deductions, and credits are reported on the individual tax returns of its shareholders, rather than being taxed at the corporate level, avoiding being taxed twice.
S corps file an annual tax return using Form 1120-S and must provide each shareholder with a Schedule K-1 detailing their share. In addition, shareholders are considered self-employed and are responsible for paying self-employment taxes on their share of the s corp’s income.
LLCs
LLCs, or limited liability companies, are often a combination of a partnership and a corporation. As a business structure, an LLC offers flexibility in terms of taxation. An LLC can choose to be taxed as a sole proprietorship, partnership, S corporation, or C corporation, depending on the number of owners (referred to as members) and their tax status.
If an LLC has only one member, it is considered a single-member LLC and is automatically taxed as a sole proprietorship. If it has multiple members, it is considered a multi-member LLC and is taxed as a partnership by default.
Both sole proprietorships and partnerships are pass-through tax entities, meaning business income is taxed through personal tax returns instead of business tax returns, avoiding double taxation.
However, an LLC can choose to be taxed as an S corp or C corp by filing an election with the IRS using Form 2553. C corp taxes are filed through the company, and S corp taxes are filed through the individual.
Still, state taxes vary by state, so we recommend consulting a professional to understand your specific tax situation.
C Corps & Sole Proprietorships
Next comes Tax Day 2026! This year, Tax Day falls on April 15, 2026. This deadline applies to C corporations and sole proprietorships, AKA businesses who report on a Schedule C, Form 1040. (This is also the tax deadline for individual income tax returns!)
C Corporations
C corporations are one of the two common types of corporations, next to S corps. Corporations involve more complexity in how they’re formed and their tax requirements. C corp taxes are filed through the company as opposed to the individual, which can be beneficial if your corporate tax rate is lower than your personal tax rate.
C corps also pay income tax and in some cases are taxed twice when the company turns a profit, and when dividends are paid to stockholders on their tax returns.
Sole Proprietorships
Sole proprietorships are the most straightforward business structure, with one person acting as the only owner and operator. In this case, the sole proprietor is personally liable for all financial and legal obligations of their business, unlike LLCs and corporations.
Sole proprietorships are a pass-through tax entity, meaning the business’s income is taxed through the owners, not the business itself. The owner reports the earnings on their personal tax return and pays taxes on their share of the profits. This type of taxation is used for sole proprietors (as well S corps, partnerships, and LLCs) to save on taxes by only taxing income once.
For more information on entity types and their different tax filing requirements, check out our blog article on business ownership structures.
If you owe more than you can pay
If you can’t afford to pay your taxes in full, you may qualify for an IRS payment plan. Options include short-term payment plans (180 days or less) and long-term installment agreements with monthly payments.
The IRS will determine what you qualify for, depending on your individual tax situation.
Learn more about setting up an IRS payment plan here.
Need more time? File a business tax extension
If you need extra time to file, don’t worry! You can file a business tax extension with Form 7004 or Form 4868, depending on your business type. Multi-member LLCs, partnerships, corporations, and S corporations all use Form 7004, but the deadline differs depending on your business’s original filing deadline.
Here are the business tax extension deadlines for 2026:
- March 16, 2026: For partnerships, S corps, and LLCs taxed as partnerships.
- April 15, 2026: For C corps and sole proprietors.
Sole proprietors and single-member LLCs use Form 4868, along with individuals filing their tax returns. The deadline for filing Form 4868 is April 15, 2025. Once you file for a tax extension, your new updated business tax deadline will be:
- September 15, 2026: Partnership and S corp tax deadlines.
- October 15, 2026: Individual, sole proprietorship, and C corp filing deadline
Check out our article on business tax extensions in 2026 for how and where to file, what forms you need, and when to make your tax payment.
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If You’re Making Estimated Quarterly Tax Payments
Estimated quarterly tax payments are based on your expected income and tax liability for the quarter, which can be calculated using last year’s tax return, your year-to-date income, or a handy tax withholding calculator.
Estimated quarterly tax payments are made using Form 1040-ES and paid online or by mail to the IRS, and they’re the best way to avoid tax penalties from the IRS.
You’re required to make quarterly tax payments if taxes have not been withheld from your income. This includes taxpayers such as:
- Individuals including sole proprietors, partners, and S corporation shareholders who generally expect to owe tax of $1,000 or more when their return is filed.
- Corporations who will likely owe $500 or more in taxes when their return is filed.
The core idea behind quarterly taxes is that rather than paying a large bill in March or April, business owners space out payments in four installments throughout the year. If done right, you can better manage your cash flow and avoid hefty underpayment fines from the IRS, such as a failure-to-file penalty or failure-to-pay penalty. It’s important to note that interest also accrues on the unpaid tax amount, top of IRS penalties.
With that in mind, let’s make sure you don’t miss a quarterly tax deadline.
There are four quarterly tax due dates each year: January 15; April 15; June 15; and September 15. However, if these dates fall on a Saturday, Sunday, or legal holiday in any given year, the payments are due the next business day.
To avoid penalties, businesses that owe $1,000+ in taxes must make estimated quarterly payments. This applies to sole proprietors, partners, and S corp shareholders.
With that in mind, here are the due dates for estimated quarterly tax payments in 2026:
- Q4 2025: January 15, 2026
- Q1 2026: April 15, 2026
- Q2 2026: June 15, 2026
- Q3 2026: September 15, 2026
Download our free quarterly estimated tax calculator to reduce the headache of calculating your payments.
Filing Taxes Late or Missing a Deadline
If you miss a business tax deadline, your options depend on two things: what deadline you missed, and whether you are owed a refund or you owe money.
If you miss your tax filing deadline & owe taxes…
If you miss the tax filing deadline and owe taxes, you’ll be charged failure-to-file and failure-to-pay penalties.
Unfortunately, penalties won’t stop there. The IRS charges interest on top of a failure-to-file penalty. The current underpayment interest rate is 7%. However, underpayment interest rates vary and are subject to change based on the quarter, so check the IRS website for up-to-date rates.
If you miss your tax filing deadline & are owed a refund…
If you miss the 2026 tax filing deadline and you are owed a refund, there’s no penalty. But you may miss out on your refund if you wait too long.
According to the IRS website, by law, you have a three-year window from the original due date to claim your refund. Don’t miss out on a refund!
If you miss a quarterly estimated tax payment…
You may face a penalty charge upon filing your tax return if you missed a quarterly tax payment – even if you’re owed a refund. If you haven’t already, add each of the quarterly tax payment deadlines to your calendar now to make sure you don’t miss one. Just scroll up!
And if you need help calculating how much you should pay each quarter, don’t forget to download our free quarterly estimated tax calculator.
If You’re Sending W-2s and 1099s
Sending a W-2 or 1099 form? Make sure you distribute these forms to your employees and independent contractors by the deadline: February 2, 2026.
There are a number of different 1099s, but the majority are filed through the 1099-NEC form or the 1099-MISC form. 1099-NEC is for non-employee compensation of $600 or more, and 1099-MISC is for miscellaneous compensation such as rent, awards, medical or healthcare payments, to name a few.
For more information on issuing and filing 1099s, check out our blog: The 1099 Form. And if you’re not sure who you should issue a 1099 to, learn which tax forms you need to issue (and when) here.
Optimize Tax Savings And Alleviate Tax Headaches With Acuity
At Acuity, we provide business tax and bookkeeping services that work together – so your books are clean, your returns are accurate, and your filings are on time.
Acuity’s team of CPAs prepare federal and state tax returns for S corps, C corps, partnerships, LLCs, and individuals, helping you maximize deductions, reduce risk, and avoid costly mistakes.
Clean books aren’t optional – they’re the foundation for accurate tax filings and real tax savings. That’s why we combine bookkeeping and tax planning in one place, giving growing businesses clarity and confidence year-round.
We’ve helped 2,700+ entrepreneurs navigate complex tax requirements and keep more of what they earn.
Explore our tax services or book a free consultation to get a personalized quote for your business.
Simplify your taxes with Acuity.
Acuity’s team of experts handle the business tax deadlines, filings, and each detail in between – all while helping you make smarter decisions as your business grows.
2026 Business Tax Deadline FAQs
Can I get an extension for filing business taxes?
Yes. Most businesses can request a 6-month extension by filing the appropriate extension form before the original deadline.
- Partnerships, S corporations, and C corporations file Form 7004
- Sole proprietors and single-member LLCs file Form 4868 (the same extension used for individual returns)
Keep in mind: an extension gives you more time to file, not more time to pay. Any taxes owed are still due by the original deadline to avoid penalties and interest.
What are the penalties for filing late or paying late?
If you miss the filing deadline and owe taxes, the IRS may charge:
- Failure-to-file penalty: Generally 5% of the unpaid tax per month, up to a maximum of 25%
- Failure-to-pay penalty: Typically 0.5% of the unpaid tax per month, also capped at 25%
Interest may also accrue on any unpaid balance, and rates can change quarterly.
What should I do if I can’t pay my taxes by the deadline?
If you can’t pay in full, it’s still important to file on time. You may qualify for an IRS payment plan or installment agreement, which allows you to pay your balance over time and can help reduce penalties.
The IRS will determine eligibility based on your specific tax situation.
How do estimated quarterly tax payments work for businesses?
Estimated quarterly tax payments are required when taxes aren’t withheld from income.
Individuals, sole proprietors, partners, and S corporation shareholders generally must make estimated payments if they expect to owe $1,000 or more when their return is filed.
Corporations are generally required to make estimated payments if they expect to owe $500 or more.
Estimated payments are typically due in April, June, September, and January of the following year.
How can I avoid making mistakes when filing my business taxes?
To reduce errors and avoid delays, we recommend following 3 protocols:
- Double-check all financial records and reports
- File electronically whenever possible
- Work with a tax professional if you’re unsure about classifications, deductions, or filing requirements
Business Tax Deadline 2025
You might be wondering why we’ve included 2025 tax deadlines here – we want to help you tie up any loose ends. Maybe you missed a deadline, filed an extension, or just want to double-check dates from last year.
Here’s a quick reference of the most important 2025 business tax deadlines:
January 15, 2025 – Deadline for Q4 2024 estimated tax payments.
January 31, 2025 – Deadline for employees and independent contractors to receive their W-2 or 1099-NEC / 1099-MISC forms.
March 17, 2025 – Deadline for partnership tax returns, LLCs taxed as partnerships, and S corporation tax returns.
(March 15 fell on a Saturday in 2025.)
April 15, 2025 – Deadline for 2025 Q1 estimated tax payments.
April 15, 2025 – Deadline for C corporation, sole proprietor (Schedule C), and individual tax returns.
June 16, 2025 – Deadline for 2025 Q2 estimated tax payments.
(June 15 fell on a Sunday.)
September 15, 2025 – Deadline for 2025 Q3 estimated tax payments.
September 15, 2025 – Extended filing deadline for partnerships and S corporations that received an extension.
October 15, 2025 – Extended filing deadline for individuals, sole proprietors, and C corporations that received an extension.