Happy New Year! The ball has dropped, the resolutions are made, and for the local business community here in Southern Illinois, the clock is officially ticking.

As we enter 2026, we are operating in a brand-new tax landscape. With the full implementation of the recent federal tax shifts, several deadlines and filing requirements have evolved. At Sharon M. Gum, CPA, located in Waterloo, IL, our goal is to ensure you never face a late-filing penalty.

The first step to a stress-free tax season is knowing exactly what is due and when. Grab your calendar and mark these essential 2026 dates.

The Early Bird Sprints: January & February

Before you can even think about your own business income tax, you have to take care of your team and your contractors. Because January 31, 2026, falls on a Saturday, the IRS has pushed the primary deadline to the next business day.

  • February 2, 2026: The “Worker” Deadline

    • W-2s: Must be sent to all employees and filed with the Social Security Administration.

    • 1099-NEC: Must be provided to any independent contractors you paid $600 or more in 2025.

    • Form 940 & 941: Annual federal unemployment (940) and your 4th quarter payroll tax return (941) are also due.

Sharon’s Pro-Tip: Don’t wait until February 1st. E-filing these forms early ensures your workers have what they need to file their own returns, reducing the number of “Where is my form?” emails you’ll receive in mid-February!

The Pass-Through Peak: March

If your business is structured as a “pass-through” entity, your deadline arrives a full month earlier than the traditional “Tax Day.” For 2026, March 15 is a Sunday, so your date is moved to Monday, March 16.

  • March 16, 2026: Partnerships & S-Corps

    • Form 1065 (Partnerships) & Form 1120-S (S-Corporations): These informational returns must be filed by this date.

    • Schedule K-1s: You must provide these to your partners or shareholders by this date so they can include the information on their personal returns.

The Grand Finale: April

This is the big one. Whether you are a solo freelancer or a large corporation, April 15 is the finish line for the 2025 tax year and the starting line for 2026.

  • April 15, 2026: C-Corps, Sole Proprietors, and Individuals

    • Form 1120 (C-Corporations): The deadline for corporate income tax.

    • Form 1040 (Sole Props & Individuals): Your personal income tax return and Schedule C.

    • Q1 Estimated Tax Payments: The first payment for the 2026 tax year is due today.

    • IRA/HSA Contributions: The final day to contribute to your 2025 retirement or health savings accounts.

Important Reminder: Extensions vs. Payments

One of the most common misconceptions we hear at our Waterloo office is that a “tax extension” gives you more time to pay. It does not.

If you file for an extension, you gain an extra six months to submit your paperwork (moving your deadline to September 15 for S-Corps or October 15 for individuals). However, you must still estimate your tax liability and pay any balance due by the original March or April deadline. If you don’t, the IRS will begin charging interest and failure-to-pay penalties immediately.

Why Local Expertise Matters in 2026

With the changes affecting everything from bonus depreciation to the way we deduct local property taxes (the SALT cap shift), the 2026 tax season is not the year to “DIY” your business filings.

As a local firm, Sharon M. Gum, CPA understands the specific needs of Waterloo business owners. We don’t just look at the federal numbers; we ensure your Illinois state filings (like the IL-1120 or IL-1065) are optimized to take advantage of state-specific credits and the new grocery tax repeal nuances.

Don’t let 2026 deadlines catch you off guard. Let’s get your books in order now so you can focus on growing your business while we handle the math.