Florida HSMV Form 85921 IFTA Tax Return Guide – Florida-based motor carriers operating qualified commercial vehicles across state lines must file quarterly fuel tax returns under the International Fuel Tax Agreement (IFTA). The official document for this purpose is HSMV Form 85921, titled International Fuel Tax Agreement, Florida Tax Return (often paired with Schedule 1). This form allows carriers whose base jurisdiction is Florida to report miles traveled and fuel purchased in all IFTA member jurisdictions and remit the correct net tax due.
What Is Florida HSMV Form 85921?
HSMV Form 85921 is the official IFTA quarterly tax return used by Florida IFTA licensees. It includes the main tax return summary and is typically filed together with Florida Schedule 1 (IFTA Fuel Tax Computations). The form captures total fleet miles, taxable miles, fuel gallons placed in vehicles, and the resulting net tax or credit for each jurisdiction.
The form is issued by the Florida Department of Highway Safety and Motor Vehicles, Bureau of Commercial Vehicle and Driver Services. Carriers report activity for qualified motor vehicles—generally those with two axles and a gross vehicle weight exceeding 26,000 pounds, three or more axles regardless of weight, or combinations exceeding 26,000 pounds gross vehicle weight that travel in more than one IFTA jurisdiction.
Official information and forms are available on the FLHSMV International Fuel Tax Agreement page.
Who Must File Form 85921?
Any motor carrier that holds a Florida IFTA license must file a quarterly tax return, even if the carrier had no operations or no fuel purchases in IFTA jurisdictions during the quarter. Florida is the base jurisdiction when the carrier’s qualified vehicles are registered in Florida for IRP purposes, operational records are maintained (or available) in Florida, and some mileage is accrued in the state.
Intrastate-only vehicles with Florida base plates are generally not subject to IFTA reporting. Recreational vehicles not used for business and certain government-owned vehicles may also be exempt, though operators should confirm requirements with each jurisdiction they enter.
Quarterly Filing Deadlines for Florida IFTA Tax Returns
IFTA tax returns are due on the last day of the month following the end of each quarter:
- January – March: Due April 30
- April – June: Due July 31
- July – September: Due October 31
- October – December: Due January 31
If the due date falls on a Saturday, Sunday, or Florida legal holiday, the next business day becomes the due date. Returns and any payment must be submitted by the deadline to avoid penalties and interest.
Approximately 30 days before each due date, the Bureau of Commercial Vehicle and Driver Services typically emails a courtesy filing notice. Tax rates for the applicable quarter are published by IFTA, Inc. and should be obtained from www.iftach.org before completing the return.
How to Complete HSMV Form 85921?
The form requires the following key information:
- Carrier name, address, Federal Employer Identification Number (FEIN), and Customer Number
- Tax period and return type (Original, Amended, or Final)
- Fuel type(s) – a separate Schedule 1 is required for each fuel type
- Total qualified fleet miles in all jurisdictions (IFTA and non-IFTA)
- Total fuel gallons placed in the tanks of qualified vehicles
- Average miles per gallon (MPG) calculated from total miles divided by total gallons
- Jurisdiction-by-jurisdiction details on Schedule 1: total miles, taxable miles, taxable gallons, tax-paid gallons, net taxable gallons, and tax or credit due
Detailed step-by-step instructions appear on the form itself and in the companion manual “How to Calculate the IFTA Quarterly Tax Return” (HSMV 85800). Accurate record-keeping of miles and fuel receipts is essential; errors can result in overpayment, underpayment, penalties, or interest.
Paper forms may be completed electronically as fillable PDFs, printed, signed, and submitted. However, significant changes are coming in 2026.
Electronic Filing Requirement Effective October 1, 2026
Under Senate Bill 488, beginning October 1, 2026, all IFTA tax return filings in Florida must be submitted electronically through the online system prescribed by the department. Paper returns will no longer be accepted after this date.
Carriers are already encouraged to use the Interstate Carrier Filing System (ICFS) for faster processing, real-time account status, online payments, and instant confirmation. Benefits of e-filing include reduced risk of lost mail, quicker processing, and access to prior returns and credit balances.
Learn more about online filing on the FLHSMV ICFS page.
Penalties and Interest for Late Filing
Late filing or late payment triggers a penalty equal to the greater of $50 or 10% of the net tax due to all member jurisdictions. Interest is also charged at an annual rate of two percentage points above the underpayment rate established under the Internal Revenue Code. Filing on time, even with a zero balance or “No Operations” return, avoids these charges.
Download Official Florida HSMV Form 85921
Download the current official PDF of Florida HSMV Form 85921 (International Fuel Tax Agreement, Florida Tax Return) directly from the Florida Department of Highway Safety and Motor Vehicles:
Download HSMV Form 85921 (PDF)
Related resources available on the FLHSMV site include:
- IFTA Forms, User Guides & Tutorials
- HSMV 85800 – How to Calculate the IFTA Quarterly Tax Return
- HSMV 85920 – IFTA Trucking Manual
- IFTA User Guide for the online system
Additional Tips for Florida IFTA Compliance
Maintain complete operational records in Florida (or make them available upon request). Keep copies of the IFTA license in each qualified vehicle and affix the required decals. When fuel tax rates change or jurisdictions update surcharge rules, always use the official rates published for the specific quarter being reported.
For assistance with Florida IFTA transactions or tax return filing, contact the Bureau of Commercial Vehicle and Driver Services Customer Service line at (850) 617-3711. Mailing address for any remaining paper submissions (prior to the October 2026 electronic mandate) is Division of Motorist Services, Bureau of Commercial Vehicle and Driver Services, Neil Kirkman Building, MS 62, Tallahassee, FL 32399-0626.
Staying current with IFTA requirements protects your operating authority and helps avoid costly penalties. File accurately, meet every deadline, and transition to the required electronic system well before October 1, 2026.