Business Tax Deadlines 2026

Filing dates and extension deadlines for S corps, partnerships, C corps, and sole proprietors — know when every business return is due.

Start filing

When are business taxes due in 2026?

Missing a business tax deadline can mean penalties that add up fast. Your due date depends on your entity type — S corps and partnerships file by March 15, while C corps and sole proprietors file by April 15. Below are the key dates for calendar-year businesses, plus how to get a 6-month extension with Form 7004.

2026 business tax filing deadlines by entity type

Business type	Form	Deadline
S corporation	Form 1120-S	March 15
Partnership / multi-member LLC	Form 1065	March 15
C corporation	Form 1120	April 15
Sole proprietor / single-member LLC	Schedule C (Form 1040)	April 15
Extension (all entities)	Form 7004	Original due date*

Business type

Form

Deadline

S corporation

Form 1120-S

March 15

Partnership / multi-member LLC

Form 1065

March 15

C corporation

Form 1120

April 15

Sole proprietor / single-member LLC

Schedule C (Form 1040)

April 15

Extension (all entities)

Form 7004

Original due date*

If a deadline lands on a weekend or holiday, it moves to the next business day.

*Form 7004 provides an automatic 6-month extension to file your business return. An extension gives you more time to file, not more time to pay. Estimate and pay any tax you owe by the original deadline to avoid interest and penalties.

Beat the deadline with TaxAct

File your business return or an extension in minutes, with step-by-step guidance and a 100% Accuracy Guarantee.

Start your business return

Business tax deadline FAQs

Small business tax filing guides & resources

Guides on estimated taxes, Schedule K-1s, S corp returns, partnership filing, and business tax extensions.

Small Business Extended Tax Return Due Dates

A TaxAct Blog guide to extended due dates for partnerships, S corps, and C corps that filed Form 7004. See each new deadline at a glance, plus why an extension to file is not an extension to pay.

What Is a Schedule K-1?

A TaxAct Blog explainer on Schedule K-1 for partners, S corp shareholders, and trust beneficiaries. Learn what each box means, when to expect your K-1, and how to report it on your personal return.

Form 1120-S: S Corp Tax Return Guide

A TaxAct Blog guide to Form 1120-S, the annual S corp return. Learn who must file, which schedules to include, and how income flows to shareholders on Schedule K-1, plus due dates and extension rules.

Form 1040-ES: Estimated Taxes for Small Business

A TaxAct Blog guide to Form 1040-ES for business owners and the self-employed. Learn how to estimate what you owe, use the worksheet, and make quarterly payments to the IRS online or by mail on time.

Form 1065: Partnership Tax Filing Guide

A TaxAct Blog guide to Form 1065, the annual U.S. partnership return. Learn who must file, how income and deductions are split among partners, how to issue K-1s, and the March 15 filing deadline.

Are Your Quarterly Estimated Payments Correct?

A TaxAct Blog guide to checking your quarterly estimated payments. Learn the safe harbor rules, how to adjust payments when your income changes mid-year, and how to avoid IRS underpayment penalties.

Over 650,000 Business Tax Returns: Based on E-filed returns completed through TaxAct Business software (Forms 1065 and 1120S) since 2003.

100% Accuracy Guarantee: If you are assessed a penalty from the IRS or state taxing authority due to a calculation error in a TaxAct product, we'll pay the penalty and interest. This guarantee does not apply if you use a TaxAct product to prepare returns for others. This guarantee does not apply if you override amounts within your tax return or if you fail to enter all required information accurately. Details at 100% Accuracy Guarantee.

Money-Back Guarantee: If you’re not completely satisfied with your TaxAct software purchase, you can request a full refund within 30 days of receipt to get your money back. No questions asked! The Money-Back Guarantee does not apply after you use the TaxAct software to print or e-file a return and that return is accepted by the IRS or state taxing agency. Read more about our Money-Back-Guarantee.

Start For Free: For online business products, you can start free and pay when you file. This means you will not be charged if you decide to stop using any product prior to printing or e-filing your return.

Xpert Assist Suite of Offerings: Tax Experts are available with TaxAct® Xpert Assist®, which encompasses a suite of services designed to provide varying levels of support and assistance for your tax filing needs. These services are available at an additional cost and are subject to limitations and restrictions. Service availability, features, and pricing may vary and are subject to change without notice. For more details, visitTaxAct Xpert Assist Terms.

Real People. Real Reviews.: All reviews are from verified TaxAct customers. Reviews are managed by Bazaarvoice and comply with the Bazaarvoice Authenticity Policy. Cumulative star rating is for all TaxAct products.

Edition Pricing: Actual prices are determined at the time of payment, print, or e-file and are subject to change without notice. Add sales tax for applicable orders. Offers may end at any time and promotional offers may not be combined.

Refund Transfer: Refund Transfers are fee-based products offered by Republic Bank & Trust Company, Member FDIC. A Refund Transfer Fee and all other authorized amounts will be deducted from the taxpayer’s tax refund.

Audit Defense: See Audit Defense provided by Tax Protection Plus (PDF) for further details of services and requirements. May not apply to certain forms and credits. Certain customers may not qualify for services based on past tax audit history, residency, or other factors. Audit Defense is not insurance. Audit Defense is subject to terms and conditions (PDF) located on Tax Protection Plus' website.

Partners: TaxAct gets fees from some third parties that provide offers to its customers. This compensation may affect what and how we communicate their services to you. TaxAct is not a party to any transactions you may choose to enter into with these third parties.

Trademarks: All trademarks not owned by TaxAct, Inc. that appear on this website are the property of their respective owners, who are not affiliated with, connected to, or sponsored by or of TaxAct, Inc. TurboTax is a registered trademark of Intuit, Inc. H&R Block is a registered trademark of HRB Innovations, Inc.