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April 2026 Business Tax Due Dates for Inland Empire Owners

For small business owners in Rancho Cucamonga, Upland, and Ontario, April is a critical month on the financial calendar. Whether you operate a busy medical practice, manage a fleet of transport trucks, or broker local real estate deals, staying ahead of tax deadlines is essential for maintaining healthy cash flow. Here are the key April 2026 due dates your California business needs to monitor.

April 15: Essential Tax Deadlines

C-Corporations: It is time to file your 2025 calendar year income tax return (Form 1120) and pay any tax due. If your business needs an automatic six-month filing extension, submit Form 7004, Application for Automatic Extension of Time to File Certain Business Income Tax, Information and Other Returns. Remember, an extension protects you from late filing penalties but not late payment penalties. You must estimate your liability and deposit what you owe using the Form 7004 instructions. Additionally, your first installment of 2026 estimated taxes is due today.

Payroll and Non-Payroll Withholding: For logistics companies and clinics following the monthly deposit rule, deposit the tax for payments made in March.

Fiduciary Returns: This is the last day to timely file a 2025 calendar year fiduciary return (Form 1041, U.S. Income Tax Return of Estates and Trusts) or to formally file an extension.

Business Accountant working on tax deadlines

Southern California Small Business Owners: Let’s Optimize Your Tax Strategy
Are you a small business owner in Inland Empire, Los Angeles, or Orange County? Let’s discuss tailored tax strategies designed specifically for small businesses in Southern California. Book your free consultation with a licensed CPA today.
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April 30: Quarterly Payroll Filings

Form 941 (Social Security, Medicare, and Withholding): File Form 941 for the first quarter of 2026. Deposit or pay any undeposited tax under the accuracy of deposit rules. If your tax liability is less than $2,500, you can pay it in full with a timely filed return. If you deposited the tax for the quarter in full and on time, your filing deadline extends to May 11.

Federal Unemployment Tax (FUTA): Deposit the tax owed through March if the total amount exceeds $500.

Weekends, Holidays, and Disaster Rules

If a due date falls on a Saturday, Sunday, or legal holiday, your deadline is automatically pushed to the next standard business day. Furthermore, property investors and local businesses should watch for disaster area extensions. When an area receives a disaster designation, deadlines are extended. Confirm declarations and adjusted filing dates via the following resources:

Want to streamline your bookkeeping and avoid deadline stress? Schedule a consultation today to explore our localized tax planning services.

Southern California Small Business Owners: Let’s Optimize Your Tax Strategy
Are you a small business owner in Inland Empire, Los Angeles, or Orange County? Let’s discuss tailored tax strategies designed specifically for small businesses in Southern California. Book your free consultation with a licensed CPA today.
Book Your Appointment
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