How to File Your IFTA Quarterly Tax Return: Forms IFTA-100 and IFTA-101

To file your IFTA quarterly tax return, you complete one Form IFTA-101 schedule for each fuel type your fleet burned during the quarter, carry the totals onto the Form IFTA-100 summary, and submit both to your base jurisdiction by the quarterly deadline with any tax owed. Your base jurisdiction then distributes what you paid to the other states and provinces you drove through. Here is how to work through the return, step by step.

Pull Your Records First

The return is a calculation, and the calculation only works if the underlying records are in order. Before you open the forms, gather two things for the quarter: distance records for every qualified power unit, and fuel purchase receipts for every gallon you want to claim as tax-paid.

Trip records need start and end dates, origin and destination, route, beginning and ending odometer or hubodometer readings, total trip distance, distance broken out by jurisdiction, and the vehicle unit number. Every mile the truck moved counts, including loaded, empty, personal, and intrastate miles. GPS tracking can stand in for manual trip sheets as long as it produces the same jurisdiction-level breakdown.¹

Each fuel receipt needs the purchase date, seller name and address, gallons, fuel type, price, unit number of the vehicle fueled, and the purchaser’s name. A receipt missing any of those fields can be thrown out during an audit, which means you lose the tax-paid credit for those gallons.¹

If you fuel from your own bulk tanks, you also need delivery receipts, quarterly inventory reconciliations, tank capacities, and a withdrawal log for every fueling event showing date, location, quantity, fuel type, and the receiving unit. The log has to cover withdrawals into non-IFTA equipment too, so an auditor can see the split.¹

Keep everything for at least four years from the later of the return’s due date or the date you filed.¹

Fill Out Form IFTA-101

The IFTA-101 is where the math happens. Complete one schedule per fuel type. Most carriers file a single diesel schedule; if any vehicles ran gasoline or propane, each fuel gets its own IFTA-101.

Fleet Numbers at the Top

Five fleet-wide figures anchor the schedule:

Item A, IFTA miles: total miles in all IFTA jurisdictions during the quarter.
Item B, non-IFTA miles: any miles run outside the 48 contiguous states and 10 Canadian provinces.
Item C, total miles: Item A plus Item B.
Item D, total gallons: every gallon of this fuel type placed into propulsion tanks during the quarter, no matter where you bought it.
Item E, average fleet MPG: Item C divided by Item D, rounded to two decimals.

Item E drives every jurisdiction calculation below. A bad MPG number contaminates the whole return.²

Jurisdiction Rows

Each jurisdiction you operated in gets its own row. If a jurisdiction charges a surcharge on top of its fuel tax, add a second row for the surcharge.

Column F: jurisdiction name and two-letter code.
Column G: rate code for your fuel type, from the quarter’s IFTA-105 rate table.
Column H, total miles: all miles in that jurisdiction for this fuel type. Enter 0 on surcharge lines.
Column I, taxable miles: miles subject to fuel tax. Exclude miles run on a temporary fuel use permit. Enter 0 on surcharge lines.
Column J: enter Item E (fleet MPG) on every jurisdiction line. Enter 0 on surcharge lines.
Column K, taxable gallons: Column I divided by Column J. On a surcharge line, copy the taxable gallons from that jurisdiction’s fuel tax line.
Column L, tax-paid gallons: gallons you actually purchased in that jurisdiction, on which tax was paid at the pump. Enter 0 on surcharge lines, since surcharges are not prepaid.
Column M, net taxable or credit gallons: Column K minus Column L. A positive number means you owe; a bracketed negative means you get a credit.
Column N: the per-gallon tax rate from the quarter’s rate table, or the surcharge rate on a surcharge line.
Column O, tax due or credit: Column M times Column N. Credits go in brackets.
Column P, interest: leave blank on a timely return. On a late return, calculate interest per jurisdiction on tax due, from the due date to the date of payment.

Total Columns O and P down the schedule to get Column Q, which is the number that moves to the IFTA-100.²

Always pull rates from the table for the exact quarter you are reporting. Rates move in some jurisdictions every quarter, and the spread is wide: the Q1 2026 diesel table runs from $0.19 to $0.971 per gallon.³⁴

Fill Out Form IFTA-100

The IFTA-100 is a cover sheet. For each fuel type, enter the Column Q total from the matching IFTA-101 on the corresponding line of the IFTA-100. A diesel-only fleet fills in one line.⁵

The form adds those lines into your total liability across all fuels. If you carried a credit forward from the prior quarter, apply it here. If the bottom line is negative, you can request a refund or roll the credit to next quarter. Sign the summary and attach every IFTA-101 behind it.

Know the Deadlines

Returns are due on the same four dates every year:

Q1 (January through March): April 30
Q2 (April through June): July 31
Q3 (July through September): October 31
Q4 (October through December): January 31

If a due date lands on a weekend or legal holiday, it rolls to the next business day. Paper returns are judged by postmark; electronic returns are judged by the portal’s timestamp.⁶

You have to file every quarter your license is active, even if the trucks stayed home. A “no operations” return with zeros keeps the account clean. Skipping a zero quarter carries the same consequences as skipping one where you owed money.⁷

Submit the Return and Pay

Send the completed IFTA-100 and all IFTA-101 schedules to your base jurisdiction, meaning the state or province where you are IFTA-licensed. Most jurisdictions run an online portal, and some require electronic filing when the return is computer-prepared.⁸ If you’re on paper, use the address on your jurisdiction’s version of the IFTA-100.

Any tax owed goes to the base jurisdiction, typically by electronic funds transfer, credit card, or check. You never send money directly to the other states or provinces; the base jurisdiction handles that redistribution. A net credit can be refunded or carried forward.

What Late or Wrong Returns Cost

The IFTA Articles of Agreement set a uniform penalty of $50 or 10 percent of the delinquent tax, whichever is greater, for a late filing, failure to file, or underpayment. The penalty applies per return, so a missed zero-operations quarter still generates the $50 minimum.⁹

Interest runs separately. For U.S.-based carriers, the annual rate is two percentage points above the IRS underpayment rate, reset each January 1, and it compounds monthly at one-twelfth of the annual rate from the return’s original due date until payment.⁹

Persistent non-filing eventually pulls your license and decals. Grounds for suspension include failing to file, failing to remit tax, failing to pay or protest an audit assessment on time, and failing to keep adequate records. A suspended license means the trucks cannot legally cross jurisdiction lines until the account is cleared.⁷

Fixing a Return After You File

If you catch an error later, file an amended return through the same channel you used originally. The amendment replaces the original, so fill it out in full rather than marking only the changes. If the corrected return shows additional tax owed, interest runs from the original due date, and the 10 percent penalty can apply to the underpayment.¹⁰

1
Iowa Department of Transportation. IFTA Record Keeping Requirements
2
New York State Department of Taxation and Finance. Instructions for Form IFTA-101
3
New York State Department of Taxation and Finance. IFTA-105 Final Fuel Use Tax Rate and Rate Code Table
4
International Fuel Tax Association. IFTA Tax Rate Matrix
5
New York State Department of Taxation and Finance. IFTA Quarterly Tax Return Form
6
Department of Revenue – Taxation. International Fuel Tax Agreement Filing Information
7
Florida Highway Safety and Motor Vehicles. International Fuel Tax Agreement Trucking Manual
8
New York State Department of Taxation and Finance. Form IFTA-100, IFTA Quarterly Fuel Use Tax Return
9
IFTA, Inc. Articles of Agreement Manual
10
Alabama Department of Revenue. If I Make a Mistake on My IFTA Quarterly Tax Return, Can I Correct It