Misryoum breaks down the most important 2025–2026 business tax return and payroll deadlines by entity type.
Deadlines can make or break a tax season, and for business owners, missing one often triggers more than just a late-fee headache.
In 2025. Misryoum highlights a clear split in business tax return deadlines: sole proprietorships and single-member LLCs typically file by April 15 using Schedule C of Form 1040. while S corporations and partnerships generally face a March 17 deadline for filing and issuing Schedule K-1s.. For many owners, getting these dates right is the first step toward staying compliant and avoiding avoidable penalties.
The next set of deadlines matters just as much because they shape your year-round cash planning.. Misryoum notes that estimated tax payments for many business types are due quarterly. with the first installment landing on April 15 in 2025 and a second payment due June 16.. Meanwhile. payroll reporting has its own timetable: W-2 forms must be sent to employees and submitted to the Social Security Administration by February 2. 2026. and those forms do not come with extensions.
This is where business bookkeeping becomes a risk-management tool. A calendar that only tracks “the big return” misses the reality that estimated payments and payroll forms create multiple compliance checkpoints.
For 2026 filings, the pattern continues but the dates shift.. Misryoum reports that calendar-year partnerships must submit Form 1065 by March 16. while S corporations with the same calendar year also file Form 1120-S by March 16.. C corporations typically have until April 15 to submit Form 1120 when operating on a calendar-year basis.
Misryoum also emphasizes that extensions follow their own rules.. For some entities. an extension can move a filing deadline—for example. certain S corporations can request an automatic six-month extension using Form 7004—but extensions generally do not change when taxes owed must be paid.. Owners who plan early can use this distinction to reduce both stress and the chance of underpayment consequences.
Looking beyond income tax returns, payroll form deadlines add another layer of operational work.. Misryoum points to the recurring structure of quarterly employment tax filings, including Form 941 due dates and Form 940 due on February 2.. For information reporting. the timeline for 1099-MISC varies by how recipients and the IRS are handled. with specific dates for recipient copies. paper filing to the IRS. and electronic submission.
Finally, the broader takeaway for business owners is simple: deadlines are interconnected across returns, estimated taxes, and payroll paperwork.. Misryoum’s key insight is that the best compliance outcomes usually come from building a single internal calendar that coordinates these streams. rather than relying on last-minute reviews before each due date.