A Florida S corporation tax return is filed on Form F-1120, but most Florida S corporations owe no state corporate income tax and only file when a federal built-in gains or excess passive income tax applies. The obligation that trips up almost every small S corp is separate from taxes entirely: the annual report filed with Sunbiz by May 1, which carries a $400 late fee the moment the deadline passes.
When Your S Corporation Actually Owes Florida Corporate Income Tax
Florida’s corporate income tax rate is 5.5% of net income.1Online Sunshine. Florida Code 220.11 – Tax Imposed For S corporations, though, Florida Statutes Section 220.13 narrows taxable income to only the amounts taxed federally under IRC Section 1374 (built-in gains) or IRC Section 1375 (excess net passive income).2Florida Senate. Florida Code 220.13 – Adjusted Federal Income Defined If neither of those federal taxes hits your return, your Florida taxable income is zero. Every corporation also gets a $50,000 exemption from Florida net income, prorated for short tax years.3Online Sunshine. Florida Code 220.14 – Exemption
Two situations create a real Florida liability, and both flow from federal taxes that pierce pass-through treatment.
Built-In Gains (IRC Section 1374)
If your company converted from a C corporation to an S corporation and sells appreciated assets within five years of the conversion, the federal government taxes the built-in gain at 21%.4Office of the Law Revision Counsel. 26 USC 1374 – Tax Imposed on Certain Built-in Gains That same gain flows into your Florida return and gets taxed at 5.5% after the exemption. Hold the assets past the five-year recognition period and this tax is gone.
Excess Net Passive Income (IRC Section 1375)
This tax applies only when two conditions coexist: your S corporation has leftover earnings and profits from prior C corporation years, and more than 25% of its gross receipts come from passive sources like rents, royalties, dividends, or interest.5eCFR. 26 CFR 1.1375-1 – Tax Imposed When Passive Investment Income If your corporation has always been an S corp, this tax cannot apply. If it applies, distributing all accumulated C corporation earnings and profits eliminates it going forward.
Filing the F-1120
The Florida Corporate Income/Franchise Tax Return is Form F-1120.6Florida Department of Revenue. Florida Corporate Income/Franchise Tax Return Form F-1120 An S corporation that owes tax under Section 1374 or 1375 completes it much like a C corporation would: start with the federal figure, apply Florida adjustments, subtract the $50,000 exemption, and calculate 5.5% on the balance. A copy of your federal Form 1120-S must be attached; without it, the Florida return is considered incomplete.7Florida Department of Revenue. Instructions for Corporate Income/Franchise Tax Return Filing and payment can be handled electronically through the IRS Modernized e-File program.
Short Form F-1120A
A shorter form is available if your S corporation owes less than $2,500 (or nothing) and meets every one of these conditions:
- Florida net income of $45,000 or less.
- 100% of business conducted in Florida.
- No additions to or subtractions from federal taxable income other than net operating loss deductions and state income taxes.
- Not included in a consolidated return at the Florida or federal level.
- No tax credits claimed other than tentative or estimated payments.
- Not required to pay federal alternative minimum tax.
Any multi-state activity or adjustment outside those listed pushes you to the full F-1120.8Florida Department of Revenue. Florida Corporate Income Tax
Deadlines and Extensions
The F-1120 is due on the first day of the fifth month after your tax year closes. For a calendar-year filer, that’s May 1, 2026, for tax year 2025.7Florida Department of Revenue. Instructions for Corporate Income/Franchise Tax Return Corporations with a June 30 fiscal year-end file by the first day of the fourth month after year-end instead.6Florida Department of Revenue. Florida Corporate Income/Franchise Tax Return Form F-1120
A six-month extension is available by filing Form F-7004 on or before the original due date.9Florida Department of Revenue. Florida Form F-7004 – Tentative Income/Franchise Tax Return and Application for Extension of Time to File Return A federal extension does not extend your Florida deadline; the F-7004 has to be filed separately. And an extension of time to file is not an extension of time to pay. Estimate any tax owed and remit it with the F-7004 to avoid penalties.10Online Sunshine. Florida Code 220.222 – Returns Due Date Extensions
One change for June 30 year-end filers: taxable years beginning before January 1, 2026, received a seven-month extension. That extra month is gone starting with 2026 tax years.10Online Sunshine. Florida Code 220.222 – Returns Due Date Extensions
Penalties for Filing Late
If you owe tax and file late, the penalty is 10% of the unpaid tax for the first month and another 10% for each additional month, capped at 50%.11Online Sunshine. Florida Code 220.801 – Penalties Failure to Timely File Returns Five months late can mean a penalty equal to half the tax. The Department of Revenue can settle or compromise penalties, but that’s discretionary.
Even with no tax due, an S corporation required to file still faces a late-filing penalty of $50 per month or partial month, up to $300. This applies only to corporations also required to file a federal return.11Online Sunshine. Florida Code 220.801 – Penalties Failure to Timely File Returns
The Sunbiz Annual Report
Completely separate from any tax filing, every Florida corporation must file an Annual Report with the Division of Corporations (Sunbiz) to stay active. The report updates the state on your principal office, officers, directors, and registered agent. The filing window is January 1 through May 1, and the fee for a for-profit corporation is $150.12Division of Corporations – Florida Department of State. Fees You can file online through Sunbiz or mail it with a check and the payment voucher; mailed payments must be postmarked by May 1.13Division of Corporations – Florida Department of State. File Annual Report
Miss May 1 and you immediately owe a $400 late fee. No grace period, no exceptions. If the report still isn’t filed by the third Friday in September, the corporation is administratively dissolved at the close of business on the fourth Friday in September.13Division of Corporations – Florida Department of State. File Annual Report Dissolution doesn’t erase your tax obligations, but it strips your ability to conduct business and can create personal liability exposure for officers. This is where small S corporations most often stumble, because the annual report has nothing to do with taxes and owners focused on their tax filings forget it exists.
Notifying Florida of Your S Election
Florida does not require a separate state-level S election; it follows your federal election. But the Department of Revenue still needs to know. If your corporation is already registered, provide a copy of the IRS Notice of Acceptance as an S corporation, or the first page of your federal Form 1120-S.14Florida Department of Revenue. What Do I Need to Do to Be Recognized as an S Corporation in Florida Skip this step and the Department may treat you as a C corporation and send notices demanding a full C corporation return.
Apportionment for Multi-State S Corporations
If your S corporation actually owes Florida CIT and operates in more than one state, you can’t report all income on the Florida return. Florida uses a three-factor weighted formula on the apportionment schedule: 25% property, 25% payroll, and 50% sales.8Florida Department of Revenue. Florida Corporate Income Tax The heavier sales weighting means a company with significant Florida customers but no in-state property or payroll can still see a meaningful share of income taxed here.
Whether you have a Florida filing obligation at all depends on nexus. Physical presence — employees, an office, inventory — creates it. Federal Public Law 86-272 offers some protection if your only in-state activity is soliciting orders for sales of tangible personal property that are approved and shipped from outside Florida, but that protection does not extend to services or digital goods.
Keeping Your Federal S Election Intact
Every favorable feature of Florida’s S corporation treatment depends on your federal S election staying valid. If the election terminates, the corporation becomes a C corporation subject to the full 5.5% Florida CIT on all net income, not just built-in gains or passive income. The federal eligibility rules are unforgiving:
- No more than 100 shareholders. Members of one family, up to six generations, count as a single shareholder.
- Only eligible shareholders. U.S. citizens and resident alien individuals, estates, certain trusts (grantor trusts, QSSTs, and ESBTs), and specific tax-exempt organizations qualify. Partnerships, other corporations, and nonresident aliens do not.
- One class of stock. Voting rights can differ, but economic rights must be identical across shares.
The most common accidental termination is issuing stock to an ineligible shareholder — a foreign investor, another corporation, or an LLC taxed as a partnership. The IRS may grant relief under the inadvertent termination rules if the mistake was unintentional, corrected promptly, and shareholders agree to any adjustments the IRS requires. Relief comes through a private letter ruling, which costs time and money. Prevention is cheaper.