IFTA refunds: how fuel tax credits come back to you

An IFTA credit is fuel tax you paid at the pump in a jurisdiction beyond what your miles there owed. Under the IFTA Articles of Agreement (R1100), you get full credit or a refund for tax-paid fuel used outside the jurisdiction where you bought it.

Each jurisdiction's line on the return compares two numbers: the taxable gallons your miles there used, which is taxable miles divided by your fleet MPG, and the tax-paid gallons you bought there. When tax-paid gallons are higher, the difference is credit gallons, and credit gallons times that jurisdiction's rate is the credit (Texas Form 56-102 instructions).

Credits net against tax due elsewhere on the same return (R1120.200). For example, a carrier that fuels mostly in one state and runs most of its miles in neighboring states shows credits in the first and tax due in the others. Only a net credit for the whole return is left to refund or carry. Our quarterly filing guide walks through the full calculation.

Surcharges never create a credit. They aren't paid at the pump, so they are figured on taxable gallons on a separate line with no tax-paid gallons to subtract.

Which fuel purchases count toward a credit?

Only fuel placed in a qualified motor vehicle, at a price that included tax paid to a member jurisdiction (R1010). You don't send receipts with the return, but you must keep them, and a valid receipt shows (P550.300):

• The date, the seller's name and address, and the fuel type
• The quantity, and the price per gallon or the total price
• The vehicle the fuel went into
• The purchaser's name: the company, not the driver

Altered or illegible receipts lose their credit unless you can show they are valid (P550.200). For your own bulk tank, only gallons withdrawn into qualified vehicles count, and only if tax was paid to the state where the tank sits (R1020.200).

An unrefunded credit carries forward to offset future IFTA tax until it is used up or eight calendar quarters pass from the end of the quarter it was earned in, whichever comes first (R1120.100).

Texas reads the window this way: a credit from the third quarter of 2018 had to be refunded or used by October 1, 2020. On that count, a third-quarter 2026 credit runs to October 1, 2028.

The Agreement only says the carry-forward stops. Illinois refunds whatever is left; other base jurisdictions apply their own law. Request the refund before the window closes rather than finding out.

Why carrying a credit costs you on a late return

A credit doesn't shield a late return. When you file late, interest on the tax due is figured before any prior credit is applied, because the money is owed to other jurisdictions (IFTA Board interpretation under R1140.200). Credits on a late return earn no interest either.

The penalty still applies too: $50 or 10% of delinquent tax, whichever is greater (R1220), and Texas charges the $50 minimum on late credit and no-tax returns as well.

You file an amended return for that quarter with your base jurisdiction. Missed fuel receipts, miles assigned to the wrong state, or a wrong fleet MPG can all leave a credit unclaimed.

• Use that quarter's rates. Rates change from quarter to quarter, so an amended return uses the rate chart for the quarter being amended, not today's.
• Send what your base jurisdiction asks for. Texas, for example, wants the original or amended Form 56-101 and Form 56-102, the refund amount, and a power of attorney if an agent files for you.
• Stay inside the records period. Records must be kept four years from the return's due date or filing date, whichever is later (P510), and that period bounds a refund. A refund request extends it until the request is granted or denied.

Your trip reports are what an amended return is rebuilt from, so the driver trip report matters as much as the receipts.