Small Business Tax Deadlines for Florida Owners: Your 2026 Calendar

If you run a small business in Florida, missing a tax deadline is one of the easiest — and most expensive — mistakes you can make. The IRS imposes penalties even when no tax is owed, and a late S-corp return alone runs $245 per shareholder per month. Here is the full 2026 calendar of dates you actually need to track.

January — close out the prior year

January 31 is your hardest deadline of the year. By this date, you must furnish W-2s to employees, 1099-NECs to contractors who earned $600 or more, and file the IRS copies of both. Miss this and the per-form penalty starts at $60 and climbs to $310 the longer you wait. If you use payroll software, automate the filing the week of January 15 so you have a buffer.

March 17 — S-corps and partnerships file

Form 1120-S for S-corporations and Form 1065 for partnerships are due March 17 (the 15th falls on a Sunday in 2026). These returns are typically the source of K-1s that flow into owners' personal returns, so filing them late delays everyone connected to the business. If you cannot file on time, request a 6-month extension via Form 7004 — but remember, the extension is to file, not to pay.

April 15 — personal returns, sole props, single-member LLCs

Form 1040 and its schedules (including Schedule C for sole proprietors and single-member LLCs) are due April 15. This is also the deadline for your first 2026 quarterly estimated payment if you owe estimated tax. If you need more time, Form 4868 grants a 6-month extension — again, only to file.

Quarterly estimated taxes — the dates business owners forget

If you expect to owe more than $1,000 in tax, the IRS requires quarterly estimated payments. For 2026 these are due April 15, June 15, September 15, and January 15, 2027. Underpayment penalties accrue from the date a quarter was due — not from April. This is the most common source of surprise penalties we see in new client returns.

Florida-specific deadlines

Florida has no state personal income tax, but if you sell tangible goods or certain services, you owe sales and use tax — most businesses file monthly by the 20th of the following month. Tangible personal property tax returns are due April 1 if your business owns equipment, furniture, or signage. Reemployment tax (Florida's unemployment) is filed quarterly with the Department of Revenue.

If you fall behind

Late filings stack penalties quickly, but they are almost always solvable. The IRS routinely grants first-time penalty abatement for taxpayers with a clean compliance history, and even longstanding back-tax situations can usually be resolved through installment agreements or, in qualifying cases, an Offer in Compromise. The worst move is to ignore the situation and let interest accrue.

If you are not sure where you stand for 2026 — or you have unfiled returns from prior years — book a free 15-minute discovery call. We will look at your situation, tell you exactly which deadlines matter for your setup, and give you a written checklist before you leave the call.