Partly, but not the way most people mean. Under IFTA you owe fuel tax on the miles you drive in each state, not on the gallons you buy there, so you cannot lower your tax bill by filling up in a cheaper-tax state. Gallons bought in a state are a credit against what you owe that state, and the quarterly filing settles the difference either way. What is genuinely worth optimizing is the total cost of a gallon, which is the pump price at that stop, minus your negotiated discount, plus that state's tax rate, and those three together do vary meaningfully across a corridor. Tax-aware purchasing means picking the stop with the lowest true net cost once tax is included, and avoiding over-buying credits in a state you barely drive through, which ties up money you get back slowly. The saving is real and worth having on every load. It is just arbitrage on net price, not avoidance of tax.
Updated August 2026 · 7-minute read
Worth being precise about, because the common shortcut version leads carriers to optimize for the wrong thing.
Partly, but not the way most people mean. Under IFTA you owe fuel tax on the miles you drive in each state, not on the gallons you buy there, so you cannot lower your tax bill by filling up in a cheaper-tax state. Gallons bought in a state are a credit against what you owe that state, and the quarterly filing settles the difference either way. What is genuinely worth optimizing is the total cost of a gallon, which is the pump price at that stop, minus your negotiated discount, plus that state's tax rate, and those three together do vary meaningfully across a corridor. Tax-aware purchasing means picking the stop with the lowest true net cost once tax is included, and avoiding over-buying credits in a state you barely drive through, which ties up money you get back slowly. The saving is real and worth having on every load. It is just arbitrage on net price, not avoidance of tax.
Yes. Nothing here is avoidance. You are choosing where to buy a commodity based on its total delivered cost, which includes tax, exactly as any buyer would. The tax you owe is unchanged and is calculated from miles driven, reported quarterly in the normal way. What changes is how much you pay per gallon at the pump, which is an ordinary purchasing decision.
It matters for the price you pay, not the tax you owe. Two stops 60 miles apart in different states can differ by a meaningful amount per gallon once pump price, your discount, and the state rate are combined. Over a few million gallons a year that difference is real money. The mistake is thinking of it as reducing your tax bill; it is reducing your fuel bill.
You can turn a purchasing decision into a financing decision. If a truck loads heavily in a state it barely drives through, the tax paid there becomes a credit that settles on the quarterly cycle rather than a saving realized at the pump. A planner that ignores this will happily recommend filling to capacity every time it sees a cheap state. Tank capacity, the remaining route, and how many miles will actually be driven in that state all have to be part of the same calculation.
Yes. Flow optimizes purchasing and is not a filing product. Carriers generally run mileage and tax reporting through their TMS or a dedicated mileage provider, and should keep doing so. The two are complements: one decides where to buy, the other reports what was driven and settles the quarter.
It varies enormously by lane mix, which is why a single figure would be misleading. A carrier crossing several state lines a day with big rate differences between them has far more available than one running mostly inside one state. Flow breaks savings out by lever in the analytics precisely so you can see what tax-aware purchasing is contributing for your operation rather than accepting an industry average.
Related: getting discounts onto every load, how to audit a savings claim, the category, compared.
A 30-minute demo runs your real corridors and shows the net cost per gallon at each candidate stop, with the tax component broken out from the discount.