Blog

We keep you up-to-date on the latest tax changes and news in the industry.

March 2026 Tax Calendar: Critical Dates for Connecticut Business Owners

March is a pivotal month here in Manchester. While we are all looking forward to the start of spring, for business owners—especially those operating S Corporations and Partnerships—this is when tax season enters its busiest phase. It isn't just about getting forms to the IRS; it's about ensuring your partners and shareholders have the documents they need to file their own personal returns.

At CPA Consulting Services, our goal is to bring clarity to this process so you can move forward with confidence. Below is a breakdown of the key deadlines hitting the calendar this month. If you are feeling behind or overwhelmed, remember that straightforward guidance is just a phone call away.

March 2: Information Returns & ACA Reporting

While the major 1099-NEC deadline passed in early February, March 2 serves as a catch-up date for several other information returns if you are filing on paper.

Business team discussing statistics and deadlines

General Information Returns (Form 1099 & 1096)

If you issued payments in 2025 requiring other variations of Form 1099 (excluding the NEC), today is the due date to file the government copies (Form 1096) with the IRS.

Healthcare Reporting (ALE Forms)

For our larger business clients classified as Applicable Large Employers (ALE), paper filings for Forms 1094-C and 1095-C are due today. If you provide minimum essential coverage and file Forms 1094-B and 1095-B on paper, this deadline applies to you as well. Note: If we are handling these for you electronically, the deadline is pushed to March 31.

You must also furnish the requisite health coverage statements (Form 1095-B or 1095-C) to your employees by this date.

Farmers and Fishermen

For our clients in the agricultural sectors, your 2025 income tax return (Form 1040) is due today if you did not pay your estimated tax by January 15. Paying the tax due now avoids penalties.

March 16: The Big Deadline for S-Corps & Partnerships

For many of our clients in Connecticut, specifically those running small businesses and S-Corps under $2M in revenue, this is the most significant date of the month. Pass-through entities must file their returns now to allow time for the personal tax returns that flow from them.

Accounting team working on S-Corp returns

Partnerships (Form 1065)

Calendar year partnerships must file Form 1065 today. Crucially, you must also provide each partner with their Schedule K-1. Without this document, your partners cannot accurately file their personal income tax returns. If you need more time, we can file Form 7004 to request a 6-month extension, pushing the filing deadline to September 15.

S Corporations (Form 1120-S)

Similar to partnerships, S Corps must file Form 1120-S and pay any tax due today. Shareholders are waiting on their Schedule K-1s to complete their personal 1040s. If you cannot file the return by today, we must file an extension (Form 7004).

Important Note on Extensions: An extension to file is not an extension to pay. If your S Corp owes tax, it must be estimated and paid by March 16 to avoid interest and penalties, even if the paperwork is filed later.

S Corporation Election (Form 2553)

Are you looking to structure your business as an S Corp for the 2026 tax year? To have the IRS treat your business as an S Corporation starting January 1, 2026, you generally must file Form 2553 by today. Filing late usually means the election won't take effect until 2027.

March 31: Electronic Filing Deadlines

Because our firm utilizes a tech-forward workflow with secure portals and electronic filing, many of the "March 2" paper deadlines listed above are effectively extended to today for our clients.

Tax forms and letters
  • Electronic Information Returns: This is the final deadline for electronically filing Forms 1099 (excluding NEC), 1098, and W-2G with the IRS.
  • ACA Forms: If filing electronically, Forms 1094-C, 1095-C, 1094-B, and 1095-B are due.

A Note on Extensions and IRS Issues

If you are a defense or security professional facing IRS debt issues, or a taxpayer who has fallen behind on filings, dates like these can be stressful. We specialize in tax resolution and helping you navigate out of debt. If you missed a deadline or received a notice, don't ignore it.

Also, keep in mind that if a deadline falls on a weekend or legal holiday, it automatically moves to the next business day. Disaster area extensions may also apply depending on FEMA declarations—we monitor these closely for our Connecticut and multi-state clients.

If you have questions about your S-Corp filing, need to request an extension, or want to discuss bookkeeping for the quarter, reach out to us. Let's make sure your business stays compliant so you can focus on growth.

Share this article...

Want tax & accounting tips and insights?

Sign up for our newsletter.

I confirm this is a service inquiry and not an advertising message or solicitation. By clicking “Submit”, I acknowledge and agree to the creation of an account and to the and .
CPA Consulting Services LLC We love to chat!
Please feel free to use the buttons below to contact us or use our Ai powered chat assistant.
Please fill out the form and our team will get back to you shortly The form was sent successfully