Business Tax Deadlines 2026: A Guide for LLCs

Tax season for 2026 is approaching fast. It’s that time of year when owners of limited liability companies (LLCs) and other business entities need to start thinking about when and how they’ll file, and whether they have everything they need. It’s essential to stay current with tax law changes and requirements, especially when managing business finances and working with professional tax accounting services.

Business income tax is different and more complex than filing individual income tax returns, including the forms you need to use, what you have to report, and even potentially the deadline for when you have to file. That might leave you wondering about the business tax deadlines for 2026. Make sure you have all the correct tax forms ready ahead of time.

When do you need to file for your LLC, and do you have everything you need prepared? We’ve created this guide to help you out. Keep reading to get all the details about the deadlines you need to know, considerations for different types of business structures, and tips to make tax preparation easier. Staying organized with your tax records can make the process smoother.

Understanding Your LLC Business Structure and Tax Classification

One of the important things you need to remember when filing for your LLC is that the forms you need to file and business tax filing deadlines can differ depending on your business structure. The four different tax classifications that LLCs can fall under for federal tax filing purposes are: 

• Sole proprietorship: A single-member LLC is considered a sole proprietor by default and will file using IRS Schedule C (Form 1040). 
• Partnership: By default, multi-member LLCs are classified as partnerships. The LLC would file an informational return using IRS Form 1065, and then each member would file with a Schedule K-1 (Form 1065). 
• S corporation: An LLC may qualify as an S corporation by default, or you can declare your LLC as a corporation by filing IRS Form 8832 to elect your classification. S-Corps are pass-through entities that avoid double taxation. After qualifying as an S-corp, the LLC would file an informational return using Form 1120-S, and each owner would receive a Schedule K-1 (Form 1120-S). 
• C corporation: LLCs can also be declared as a C corporation by filing IRS Form 8832. The business is then taxed as a separate entity by filing Form 1120, and any dividends distributed would be subject to double taxation. This classification is subject to corporate income tax.

Each of these business structures can come with pros and cons for tax filing purposes. Professional tax preparers can help you decide which option is best for your business, so you file in the most optimal way. The right advice can also help you handle certain business income tax situations.

How Are LLCs Taxed as Pass-Through Entities?

As mentioned above with S corporations, some forms of LLCs are taxed as pass-through entities that avoid double taxation. Sole proprietorships, partnerships, and S corporations will all be taxed as a pass-through entity when you file. These entities typically allow you to report taxable income on your personal return.

LLCs are taxed as pass-through entities because each owner will report profits and losses from the business on their personal income tax returns and pay taxes at their individual tax rates. In this case, you still need to pay federal income tax based on your share.

That differs from double taxation, where the business would be taxed at the corporate level first, and then shareholders would also pay taxes on any dividends they receive. The only type of LLC that receives double taxation is a C corporation. C corporations may also be subject to specific excise taxes.

Why Does Your Tax Year Matter for Filing Deadlines?

The tax year matters when you’re filing taxes as an LLC because it establishes the 12-month period you’re reporting for. Most types of LLCs, including sole proprietorships, partnerships, and S corporations, will operate under a traditional calendar year from January 1st to December 31st. Then, you’d need to file taxes by the 15th day of the third or fourth month after the year ends. These entities are typically not fiscal year taxpayers.

Alternatively, C corporations can choose a fiscal year that aligns best with their accounting and financial reporting needs. The fiscal year would be a period of 12 consecutive months that ends on the last day of a month other than December. Then, they’d need to file taxes by the 15th day of the fourth month after their established fiscal year ends. For example, a C corporation may have its fiscal year end on June 30th and would need to file by October 15th. These C corporations are considered fiscal year taxpayers.

Annual Business Income Tax Filing Deadlines for LLCs in 2026

The LLC tax deadlines for 2026 are: 

• March 16th, 2026, for partnerships and S corporations
• April 15th, 2026, for sole proprietors

C corporations operating on a traditional calendar year from January 1st to December 31st would also need to file by April 15th. 

Quarterly Estimated Tax Payment Deadlines You Need to Know

LLCs that are expected to earn $1,000+ per year are required to make quarterly tax payments. Quarterly estimated taxes are based on what the business paid the previous year or expects to make during the current year. Failure to make quarterly payments can result in penalties that you have to pay when filing annual taxes for the year. 

When Are the Four Quarterly Estimated Tax Deadlines in 2026?

The deadlines for quarterly taxes in 2026 are: 

• April 15th, 2026, for first quarter earnings in 2026
• June 15th, 2026, for second quarter earnings
• September 15th, 2026, for third quarter earnings
• January 15th, 2027, for fourth quarter earnings

Working with a professional accounting and tax preparation service can help LLCs efficiently manage quarterly payments to ensure accurate reporting and prevent missed deadlines. 

Which Business Entities Must Make Estimated Tax Payments?

Any form of LLC that expects to earn $1,000+ during the year will need to make quarterly payments. That includes sole proprietorships, partnerships, S corporations, and C corporations. 

Additionally, those who are self-employed or independent contractors will also need to make quarterly payments if they expect to make more than $1,000. 

Employment Taxes and Contractor Reporting Deadlines

If your LLC has employees, you’ll also need to report, withhold, and pay federal income, social security, medicare tax, and federal unemployment tax. Plus, you’ll need to report services from independent contractors that you paid for during the year. 

Deadlines in 2026 for employment and contractor reporting include: 

• Form W-2 needs to be sent to all employees and the Social Security Administration by February 2nd, 2026. 
• Form 1099-NEC needs to be sent to any contractors, freelancers, or vendors you paid more than $600 to for business services, and reported to the IRS, by January 31st, 2026. 
• The Employer’s Annual Federal Unemployment Tax Return (Form 940) needs to be filed by February 2nd, 2026. 
• The final quarterly filing date for the Employer’s Quarterly Federal Tax Return (Form 941) is February 2nd, 2026. 

How to Request a Business Tax Extension and Avoid Penalties

Not filing business taxes by the established deadlines can result in penalties that you have to pay. Fortunately, if you run out of time to get the required paperwork together, the IRS has options to help you extend the deadline by 6 months. Sole proprietors will need to file Form 4868, and partnerships, S corporations, and C corporations will need to file Form 7004 to get an automatic 6-month extension of the deadline.  

It’s important to note that this is just an extension to file the required paperwork to report annual business taxes. You still need to make an estimated payment for how much you owe when filing for an extension to avoid the failure to pay penalty and interest charges for unpaid taxes. 

What Happens If You Have Unpaid Taxes After April 15?

When you have taxes owed after the April 15th deadline, the IRS will charge you a failure-to-pay penalty and interest each month until you pay your tax balance in full. They will also send you a notice through the mail that you still owe taxes for the year. 

If this happens, it’s best to work toward paying your taxes in full as soon as possible, since interest will add up. The IRS also offers payment plans to help those who owe taxes pay them back by a scheduled date. 

The IRS’s payment plans include a short-term payment plan that allows you to take 180 extra days to pay and longer-term payment plans up to 72 months. Long-term payment plans will have a higher interest rate than the short-term plan. 

If you have unpaid taxes after April 15th and don’t think you’ll be able to make a full payment quickly, it’s a good idea to sign up for one of the payment plans as soon as possible and start making monthly payments to show the IRS you plan to pay. 

How to Manage Tax Season Without the Stress

Managing all the tax deadlines required for LLCs, along with accurate reporting and making all the deductions you may qualify for, can add a lot of stress for business owners. While it can feel tempting to try to manage it all on your own, it can create more challenges when you have a business to run or encounter any reporting issues. 

Fortunately, services are available that can lend expertise and make the process a lot easier. Hiring a tax professional or tax preparation service is a great place to start. Professional tax preparers are well-trained to handle business reporting, filing deadlines, and deductions accurately, helping take work off your plate while reducing the risk of penalties or audits. 

When you’re looking for a great option, our virtual tax preparation services at Milestone can help. Our services are built to handle the needs of small to mid-sized businesses in a variety of industries. We take the time to learn about your business, act as a partner in the process, and offer insights to help you optimize for success when you file your taxes. 

Ready to see how tax preparation services can help? Contact us today to learn more about how our team at Milestone can help your LLC manage taxes efficiently and accurately.