IFTA, Minus the Confusion

IFTA runs on calendar quarters, and a quarter's return comes due on the last day of the month after it closes: April 30, July 31, October 31, January 31. When one of those dates lands on a weekend or a holiday it moves to the next business day, which is why two of the four dates below don't match the pattern.

• Q2 2026 (Apr–Jun): due Friday, July 31, 2026
• Q3 2026 (Jul–Sep): due Monday, November 2, 2026 (Oct 31 is a Saturday)
• Q4 2026 (Oct–Dec): due Monday, February 1, 2027 (Jan 31 is a Sunday)
• Q1 2027 (Jan–Mar): due Friday, April 30, 2027

Two things about that calendar. The date is the same whether you owe money, are owed a credit, or land exactly on zero — the return is a report of miles and gallons first and a payment second, and the report is what's due. And a quarter with no operations doesn't automatically mean nothing to file; check your base jurisdiction's instructions before you assume you can skip one.

Weekend and holiday shifts follow the general next-business-day rule, but your base jurisdiction publishes the date it actually enforces and that date is the final word. If you're going to be late, what that costs is set by the agreement and your base jurisdiction — not by anything we could usefully print here.

IFTA isn't an extra tax. It's a redistribution mechanism, and once you see what it's redistributing the arithmetic stops feeling arbitrary. When you buy diesel you pay that state's fuel tax at the pump, whether or not you burn a drop of it inside its borders. When you cross a state without stopping, you use its roads and hand it nothing. The quarterly return squares those two facts: it works out how much fuel you actually consumed in each jurisdiction, compares that to how much tax-paid fuel you bought there, and moves the difference. That's why one return can produce a credit in one state and a bill in the state next door, on the same quarter, in the same truck.

Whether any of this applies to you at all turns on whether you're running a qualified motor vehicle in two or more member jurisdictions. The weight and axle thresholds that make a vehicle qualified are defined in the agreement itself — look them up rather than guessing, because that single definition decides whether the rest of this page is your problem or somebody else's.

IFTA isn't a tax on where you buy fuel — it's a tax on where you burn it. The return reconciles the two:

1. Fleet MPG = total miles in all jurisdictions ÷ total gallons consumed by your qualified vehicles for the quarter. (Consumed — if you run bulk fuel or carry meaningful tank inventory across quarter lines, that's not identical to gallons purchased.)
2. Taxable gallons per state = your miles in that state ÷ fleet MPG.
3. Net gallons = taxable gallons − tax-paid gallons you purchased in that state (gallons, from your receipts — not a dollar figure).
4. Tax or credit = net gallons × that state's rate from the official matrix. Negative = credit. Sum across states = your return.

Fleet MPG is the hinge the whole return turns on

Notice that every per-jurisdiction figure descends from one number. Miles in a state don't generate tax by themselves — they generate gallons, and they generate them by division. Get the divisor wrong and every line on the return is wrong at once, in the same direction.

Here's what that looks like with real arithmetic. A truck runs 12,000 miles for the quarter and consumes 1,600 gallons, so fleet MPG is 12,000 ÷ 1,600 = 7.5. Of those miles, 1,800 were in Indiana, where you bought 150 gallons at the pump. Indiana's taxable gallons are 1,800 ÷ 7.5 = 240; subtract the 150 tax-paid gallons and the net is 90 gallons — you owe on 90 gallons at whatever rate the matrix currently shows. Run the same quarter through Illinois: 2,400 miles driven, 500 gallons purchased. Taxable gallons are 2,400 ÷ 7.5 = 320, tax-paid is 500, net is −180 — a 180-gallon credit, because you paid Illinois for fuel you carried across the line and burned somewhere else.

Now break one input. Suppose 100 gallons never made it into the total — a receipt lost in a door pocket, a bulk-tank draw nobody wrote down. Reported fleet MPG climbs to 12,000 ÷ 1,500 = 8.0, and Indiana's taxable gallons fall from 240 to 225. One gap moved Indiana by fifteen gallons, moved every other jurisdiction on the return at the same moment and in the same direction, and — if those gallons were genuinely purchased somewhere — threw away the credit they were worth as well. That is the entire reason the people who chase down the last receipt aren't being fussy about it.

The three surcharge states

Indiana, Kentucky, and Virginia each appear on the matrix twice: once with an ordinary fuel rate, and once again on a separate surcharge row. The surcharge is assessed on the gallons you consumed in that jurisdiction — the 240 figure from the example above, before any subtraction. The trap is that the surcharge line has nothing to deduct against it: buying fuel in Indiana pre-pays Indiana's fuel tax, but it does not pre-pay Indiana's surcharge.

This is the single most reliable surprise in the whole process. A driver who deliberately tanks up in a surcharge state, assuming the receipts will cancel the liability, opens the finished return and finds a balance owing there anyway. Nothing has gone wrong; the surcharge was never built to be offset at the pump. The practical version is that miles through those three jurisdictions carry a cost that miles elsewhere don't, and a route comparison based on pump price alone is missing a line item. Pull up your own base jurisdiction's return form and find the surcharge rows before your first filing rather than during it.

Oregon sits outside the fuel-tax model

The matrix shows no ordinary fuel rate for Oregon, because Oregon doesn't collect from heavy vehicles through an IFTA fuel rate at all. It uses a weight-mile tax — a separate system with its own reporting, keyed to how heavy you are and how far you went rather than to gallons.

That leaves two consequences worth separating. Your Oregon miles still belong in your total miles, because total miles is the numerator that produces fleet MPG; drop them and your MPG inflates, which quietly understates taxable gallons in every other jurisdiction you ran. But those same Oregon miles produce no IFTA fuel-tax line of their own. Seeing "no rate" next to Oregon and concluding that Oregon miles don't count anywhere is the more expensive of the two mistakes available here.

Cousins to know about

• Kentucky KYU — a weight-distance tax of $0.0285/mile for vehicles over 59,999 lb combined license weight (KRS 138.660), on top of the IFTA surcharge. Separate license, separate filing. A thousand Kentucky miles is 1,000 × $0.0285 = $28.50, and it is owed regardless of what your IFTA return did.
• New York and New Mexico also operate weight-distance taxes with their own registrations. We don't reprint their figures; if you run either state, get the current numbers from that state's own agency instead of assuming your IFTA return absorbed them.

Every figure on a return is supposed to come out of a record you already have, not out of an estimate you assemble in the last week of the month. The specifics — accepted formats, how long you hold things, what your base jurisdiction wants to see — are set by the agreement and by that jurisdiction, so read theirs. But the shape is the same everywhere, and it's two families of paper.

Distance records have to resolve miles down to the jurisdiction. If you run an ELD or a GPS-based mileage system, most of this is produced for you and your job is checking it rather than building it. If you don't, it's trip sheets: dates, route, beginning and ending odometer, and where you crossed each line. The weak point is almost never the highway miles. It's the deadhead, the reroute around a closure, the yard-to-yard move nobody wrote down.

Fuel records have to resolve to gallons, purchased in an identified jurisdiction. This is where people get caught: a credit-card statement showing a dollar amount is not a fuel record for these purposes. The return runs on gallons, and dollars can't be converted back into gallons afterwards without knowing the exact pump price you paid that day. Keep the receipt. If you draw from your own bulk tank, the record you need is what went into the qualified vehicle, not what went into the tank.

The argument for keeping these as you go is arithmetic, not virtue. A return built from complete records is an afternoon's work. A return reconstructed backwards from card statements, memory and a road atlas takes days, produces numbers you can't defend if anyone asks, and is still due on exactly the same date. And the records — not the return — are what an audit examines. The return is only your summary of them.

This page explains a mechanism. It doesn't have your numbers, and there are three things it structurally cannot supply.

The current rates. Fuel tax rates move quarterly, jurisdiction by jurisdiction, and a rate that was correct last quarter is simply a wrong answer this quarter. That's why the table here is a link rather than a copy — the matrix at iftach.org is the authoritative version, it gets updated in place, and any figure we reprinted would begin going stale the day it was published. Q3 2026's rates are still marked provisional there until early September, which is its own argument against memorising any of them.

Your miles. Only your own distance records know where the lines fell on your routing. Jurisdictions also differ on which miles are taxable at all — certain categories are treated as non-taxable in some places and not in others — and whether any of yours qualify is a question for your base jurisdiction's instructions, not for a web page that has never seen your trip sheets.

Your filing. Nothing here transmits anything, knows your account, or checks your work. If you're a company driver, your carrier holds the license and files; if you're leased on, the settlement statement is where you find out who's actually carrying it and who eats the balance. Ask that question before the quarter closes rather than after.

Which is the RecapHours position generally. The value in doing this arithmetic yourself is that you walk into the filing already knowing what fleet MPG the quarter produced and which jurisdictions are going to come back as credits — so a number that looks wrong reads as wrong to you immediately. That is a different thing from being told you're square with anyone. We'll help with the first. The second is between you, your base jurisdiction, and the return you sign.